Electric Arc Welding Procedure: A Complete Practical Guide

Two welders, the same 6 mm steel bracket, the same E7018 rod — and one passes inspection while the other has to grind out a cracked fillet. Nothing about the rod changed. What changed was the procedure: amperage, travel speed, arc length, preheat and clean-up. That gap between ‘I know how to weld’ and ‘I can weld to a repeatable, defensible procedure’ is exactly what this guide closes.

What an Electric Arc Welding Procedure Actually Is (and Why It Matters)

That cracked fillet came down to four numbers and one habit. Both welders ran E7018 on the same 6 mm bracket, but one was pulling 230 amps, dragging a long arc, and pushing the bead at nearly twice the speed the joint wanted. The other held 190 amps, kept a tight arc, let the plate cool between passes, and ground the root clean. Same rod. Different procedure.

Here is the direct answer: an electric arc welding procedure is the written, repeatable set of instructions that governs how a specific weld is made. It tells anyone in the shop what process to use, which filler metal, how the joint is prepared and cleaned, what amperage, voltage and travel speed to hold, how much preheat to apply, and what the finished weld must look like before it is accepted.

The Four Levels People Mix Up

Most shop-floor confusion comes from treating four documents as if they were interchangeable. Each answers a different question.

Level	What it is	The question it answers
Welding process	The physical method: SMAW (stick), GMAW (MIG), FCAW (flux-cored), GTAW (TIG) or SAW (submerged arc)	How does the arc heat and join the metal?
Welding Procedure Specification (WPS)	The instruction sheet a shop follows	How do I make this weld?
Welding Procedure Qualification Record (PQR)	Test data proving those parameters work for this base metal, filler, position and thickness	Does this procedure actually produce an acceptable weld?
Welder Performance Qualification (WPQ)	The individual welder’s test record	Can this specific person make a compliant weld?

Think of it as a chain. The WPS is the how-to. The PQR is the evidence that the how-to works, and the WPS is built on it. The WPQ is personal: it proves a named welder welded to the standard in the stated position. A perfect WPS still leaves you non-compliant if the welder running the arc was never qualified to it.

The American Welding Society splits its certification endorsements along the same lines, with a Welding Procedure Qualifier (WPQ2) endorsement for the procedure and a Welder Performance Qualifier (WPQ1) endorsement for the individual. If the body that writes the codes treats those as separate achievements, so should your shop.

Why Code Work Cannot Skip the Paperwork

For pressure piping, structural steel, bridges, tanks and anything governed by the ASME codes or AWS structural codes, a documented, qualified procedure is a condition of doing the work. A contractor can quote the best price in the country and still be sent home if the PQR for that joint is missing or does not cover the thickness on the drawing.

The scale of that document set explains why shops get so paperwork-heavy. The American Welding Society states it has authored more than 350 standards covering welding practices and procedures, and its codes page currently lists AWS D1.1/D1.1M:2025-AMD1 for structural steel, AWS D1.2/D1.2M:2026 for aluminium, AASHTO/AWS D1.5M/D1.5:2025 for bridges, and AWS A3.0M/A3.0:2025 for nondestructive examination terminology and acceptance criteria. Add ASME volumes, client specs and insurer paperwork, and a good procedure saves weeks at pre-fabrication instead of costing an afternoon.

The discipline pays off outside code work. A small fab shop making the same bracket every month gets consistency between shifts, a training baseline for new welders, and a defensible answer when a customer asks why the last one cracked. That is why this guide works for a one-person repair shop too.

A Procedure Has to Match the Machine on the Job

A procedure is not machine-agnostic. OSHA 29 CFR 1910.254(d)(6) requires that the printed rules and instructions covering operation of equipment supplied by the manufacturer be strictly followed. The parameter sheet must match the power source in front of you: output range, duty cycle, arc characteristics and controls. A procedure tuned for a constant-current stick machine does not transfer cleanly to a multi-process inverter set to pulse or double-pulse, and nobody should adjust it without requalifying.

Hot work carries paperwork of its own. OSHA 29 CFR 1910.252(a)(2)(iv) requires cutting or welding to be authorized by the individual responsible for the area, preferably in the form of a written permit. A WPS does not replace a hot work permit; the two live in different binders.

The AWS says demand for skilled, qualified welders is at an all-time high, and the National Institute for Occupational Safety and Health continues to document the long-term health exposure of people who weld for a living. Written procedure is how a shop protects both the weld and the welder.

What You Will Be Able to Do by the End

By the end of this guide you should be able to choose the right arc process, read and write the parameters that matter, spot the warning signs of an unqualified procedure, and fold safety requirements into the same document.

• Choose a process and see why SMAW still earns its place on dirty, outdoor, all-position work in our guide to why stick welding still wins.
• Set up a machine properly, including gas, wire and shielding, using the complete practical guide to MIG welding.
• Select filler metal by matching strength and alloy system, starting with the all-position welding rod guide for stick consumables.
• Protect yourself and the job with the right PPE and shop gear in the welding supplies buyer’s guide.

One last framing: a procedure is not bureaucracy for its own sake. It is the shortest possible answer to the question every fabricator eventually faces. Why does this weld look like this?

How Electric Arc Welding Works — The Variables That Set Your Procedure

At its core, electric arc welding is controlled melting. Strike an electrode to the workpiece and a sustained arc forms between the two, melting the base metal and any filler being introduced. As you travel, that molten pool cools and solidifies into a weld bead. The goal of any procedure is simple: keep that pool stable, fused to the joint, and safe from the air while it is still liquid.

Shielding: Keeping Contamination Out

Molten steel reacts aggressively with oxygen, nitrogen and hydrogen. To prevent that, each process uses a form of shielding:

• SMAW (stick): The flux coating on the electrode decomposes, creating a gas shield and a layer of slag to chip off between passes.
• GMAW (MIG): An externally supplied shielding gas, most often an argon and CO₂ blend, is forced through the welding gun.
• GTAW (TIG): A non-consumable tungsten is protected by external shielding gas, usually pure argon.
• FCAW: A flux core within the wire provides shielding, either self-shielded or with an added gas blanket.
• SAW: The arc is fully buried under a blanket of granular flux, which both shields the pool and forms slag.

Shielding isn’t optional. Flow rate, gas blend and coverage matter greatly, especially outdoors. For a breakdown of supply and blending, see our guide to air gas welding explained.

Key Procedure Variables

Every one of these settings changes the weld, and all of them should be accounted for on a written procedure.

Variable	Why it matters
Current (amperage)	Controls penetration, melt rate and deposition. Too low risks lack of fusion or stubbing, too high risks undercut and excessive melt-through.
Voltage / arc length	Sets arc spread and bead shape. Voltage tends to rise with arc length, directly affecting how much filler enters the pool.
Travel speed	Dictates heat per millimetre. Slower increases heat input and bead size, faster reduces it for a narrower, more convex bead.
Electrode or wire diameter	Limits the usable amperage range and the bead size that can fit a specific joint.
Polarity	DCEP puts around two-thirds of heat into the work for deeper penetration, while DCEN puts more heat into the electrode, ideal for GTAW on thin or heat-sensitive metals.
Work and electrode angle	Directs arc force and filler to the joint. Poor angles often lead to undercut, poor fusion or a wandering bead.
Preheat and interpass temperature	Controls cooling rate to lower the risk of cracking, especially on thicker or restrained joints.
Shielding gas type and flow rate	Affects arc stability, penetration, spatter and the overall integrity of the pool.

Once these are set, consumable selection brings them to life. Our all position welding rod guide covers classifications, while the alloy steel welding electrode guide goes over selection, storage and safety. For outdoor or dirty steel work, the advantages of stick welding are still hard to beat.

Heat Input: The Number That Ties It Together

The simplest way to quantify energy applied to the joint is heat input:

Heat input (kJ/mm) = (Voltage × Amperage × 60) ÷ travel speed (mm/min) ÷ 1000

For example, 24 V, 200 A and 150 mm/min equals 1.92 kJ/mm. Raising travel speed to 220 mm/min with the same arc drops it to 1.31 kJ/mm. This is arc energy, not all of which reaches the metal. Multiplying by an efficiency factor (commonly around 0.8 for SMAW and GMAW) gives effective heat input. However, codes such as the AWS D1.1/D1.1M structural steel standard use their own tabulated factors, so always follow the governing code when one applies.

Too much heat widens the heat affected zone, coarsens grains and increases distortion. Too little heat risks lack of fusion or, with hydrogen present, cold cracking.

Transfer Modes, Arc Length and Electrical Limits

In GMAW, transfer mode is just as important as amperage. Short circuit transfer uses low heat for thin material and out-of-position work. Globular sits in the middle with larger droplets and more spatter. Spray transfer offers a stable, nearly spatter-free stream, but only works in a narrow window, realistically limited to flat and horizontal positions. Changing wire feed or current can shift between these modes and change the weld entirely.

Of all variables, arc length is the hardest to hold by feel. Too long creates spatter and poor fusion, too short can cause stubbing or cold laps. A sound procedure will call for a voltage band or a target arc length, not a vague phrase. For TIG-specific control on thin and reactive metals, see our aerospace TIG welding guide.

Finally, electrical safety is part of the procedure itself. OSHA 29 CFR 1910.254(b)(3) limits open-circuit voltage to 80 volts for AC manual arc welding and cutting, and 100 volts for DC manual arc welding and cutting. 1910.254(d)(8) prohibits splices in welding cables within 10 feet (3 m) of the electrode holder. These are backed by the wider requirements in OSHA 1910.252 and 1910.253, making it clear that the procedure must match the machine being used.

Choosing the Right Arc Process: SMAW, GMAW, FCAW, GTAW and SAW Compared

There is no best welding process. There is only the process that suits the joint, the metal, the position your body will be in and the shop you are standing in. The question is not which process is strongest, but which gets a compliant weld repeatably given your constraints.

SMAW (Stick): the self-sufficient one

SMAW arcs between a consumable electrode and the workpiece, with the flux coating doing the shielding. As it burns, the coating breaks down into shielding gas and a slag layer that floats on the molten pool, and no gas bottle is needed, which makes stick the most portable process in the shop.

AWS classifies electrodes: an E means arc welding electrode, the first two digits give tensile strength in thousands of psi (so 70 means 70,000 psi), and the last digit or digits describe coating type and usable polarity. E6013, E6010 and E7018 are everyday examples.

Stick is comfortable in almost any position, tolerates wind, rust, mill scale and paint that would wreck a gas-shielded arc, and needs only a modest power source. Its case for stick welding is about independence and robustness. The price is speed and cleanliness: low deposition rate, constant slag removal, and heavy fume and spatter per kilogram of weld metal.

GMAW (MIG): the production workhorse

GMAW feeds a continuous consumable wire through the torch and relies on externally supplied shielding gas, usually a mix such as 75% argon with 25% carbon dioxide, to displace air from the arc zone. You never change electrodes, so the arc stays up and deposition climbs well above stick. The bead is smooth, spatter moderate, and needs less dressing than a SMAW pass.

GMAW needs clean metal: rust, mill scale, oil, paint and moisture cause porosity, and shielding gas means managing flow rates, hoses and leak checks. Transfer mode matters. Short-circuit gives a small, cool pool suited to thin material and out-of-position work, globular is the middle ground, and spray throws a hot, fast, flat bead onto thicker plate. Spray on a 6 mm fillet in vertical-up is how shops end up with cold-lapped welds. Many first meet it through aluminum MIG welding, where the same gas and transfer logic applies with different consumables.

FCAW (Flux Cored): deposition without a gas bottle

FCAW uses a tubular wire with flux inside it. Self-shielded wire generates its own shielding from the flux core, so it needs no gas cylinder, which suits field and outdoor fabrication. Gas-shielded FCAW adds shielding gas to reduce fume and spatter. Both are all-position capable and deposit metal fast, which is why FCAW dominates shipbuilding and heavy structural steel. The cost: more spatter, more slag removal and a heavier fume load than GMAW. On a windy site with thick structural sections, that is a trade most fabricators accept gladly.

GTAW (TIG): control over heat

GTAW uses a non-consumable tungsten electrode and an inert shielding gas, typically argon, with filler metal added separately by hand if the joint needs it. With no consumable electrode governing the heat, the welder controls arc length and heat directly, and can add no filler at all for some joints.

That control makes GTAW standard for stainless steel and aluminium, for thin wall and for root passes that will be examined, and it gives the cleanest, most cosmetic welds of any arc process. The downsides are speed and sensitivity: it is the slowest of the common processes, and a contaminated tungsten, a dirty coupon or a leaky gas line causes unpicklable discolouration in seconds. For aerospace or pressure-vessel work, read aerospace TIG welding practices, where preparation discipline is everything.

SAW (Submerged Arc): the industrial heavyweight

SAW carries the arc under a blanket of granular flux that protects the weld from the atmosphere, so it produces the lowest fume level of the common arc processes with the highest deposition rate. It excels on thick plate and long seams. The catch is that it is mechanised: wire and flux feed from separate units, the joint sits in a fixed position, and the setup is built for repeat production, not a one-off repair. For a single 20 mm fillet, the machine time is usually not worth it.

The WPS, the PQR and the Codes: Turning a Good Weld Into a Qualified One

Plenty of welders produce a fillet that passes code inspection on Tuesday and fails it on Thursday with the same rod, steel and machine. The reason is rarely skill. It is paperwork. Between the good weld and the qualified weld sits a chain of documents, and until every link is closed the job is unproven.

That chain has three named parts, and confusing them is a common source of wasted money in fabrication.

Three documents, three different jobs

Document	What it is	Who signs it
WPS (Welding Procedure Specification)	The instruction set the shop follows: process, consumable, joint detail, preheat, parameters, technique, cleaning.	A qualified person, usually the welding engineer or a Level III/Level IV specialist.
PQR (Welding Procedure Qualification Record)	Test data proving those parameters produce an acceptable weld for the base metal, filler, position and thickness.	Qualified by testing, recorded in a standard format, reviewed by the organization.
WPQ (Welder Performance Qualification)	Proof that a named individual welder can make a compliant weld in the qualified positions.	Signed by the welder and the manufacturer or authorized inspector.

Think of it the way a kitchen does: the WPS is the recipe, the PQR is the test kitchen proving the recipe works, and the WPQ is the licence showing the cook can execute it. A shop can hold a flawless WPS and still be non-compliant if the welder on the pipe is not qualified to that procedure.

Essential versus non-essential variables

Codes separate what you may change freely from what forces you back to the drawing board. Essential variables generally include the welding process, the base metal specification or group, the filler metal classification, the welding position, the thickness range (and, for tube, the outside diameter), and the minimum preheat and interpass temperature. Change any of these and the procedure must be requalified.

That last one catches people. If your qualified PQR used a specific alloy steel electrode classification and you switch to another, you are no longer welding to a qualified procedure. You may also have moved outside the thickness range or welded a vertical-up position the test never covered.

Non-essential variables are the everyday things you can still adjust within limits: ambient temperature, some joint design details, minor gas flow variations. The codes list them explicitly, and that boundary is what keeps a qualified procedure from quietly drifting out of date.

Which code governs the job

The governing document decides everything: which qualification test counts, what essential variables apply, and what the inspection and acceptance criteria are. The AWS codes and standards page currently lists AWS D1.1/D1.1M:2025-AMD1 for structural steel and AWS A3.0M/A3.0:2025 for nondestructive examination terminology and acceptance.

Document	Covers
AWS D1.1/D1.1M	Structural steel. Clause 5 covers qualification of welding procedures; Clause 6 covers inspection and acceptance, including visual and NDT.
AWS D1.2/D1.2M	Aluminium structures. Distinct qualification rules, and the reason aluminium MIG welding has its own procedure logic.
AWS D1.5/D1.5M	Bridge and highway structures.
AWS A3.0M/A3.0	NDT terminology, personnel qualification and acceptance criteria.
ASME BPVC Section IX	Qualification of welders and welding procedures for ASME code work.
ASME B31.3	Process piping. The 2024 edition runs 592 pages covering materials and components, design, fabrication, assembly, erection, examination, inspection and testing of piping. Revisions touch heat treatment (paras. 330.1, 331.1), impact testing (paras. 323.2.2, 323.3.1) and flange attachment welds (para. 328.5.2). See the ASME B31.3 page.

Here is the point that saves real money: a welder qualified to AWS D1.1 is not automatically qualified under ASME Section IX, and a WPS approved for one code does not satisfy another. Different qualification tests, ranges and acceptance criteria. If a client wants structural and ASME code work in the same month, you are looking at two qualification chains, not one.

Inspection: eyes first, then the expensive tools

Every coded weld starts with visual inspection. OSHA 1910.252 treats welding inspection as a safety and quality function, and visual checks (profile, size, cracks, undercut, porosity, spatter, continuity) catch the majority of defects at almost no cost. Only after visual acceptance does non-destructive examination come into play.

Method	Best at finding	Limitations
Radiography	Internal volumetric defects: porosity, slag, lack of fusion	Slow, costly, radiation controls
Ultrasonic	Internal planar and volumetric flaws in thicker material	Operator-sensitive, needs skilled personnel
Magnetic particle	Surface and near-surface cracks in ferromagnetic material	Only works on magnetic materials
Dye penetrant	Fine surface-breaking defects on non-porous materials	Surface only, needs a clean surface

None of them proves a procedure is right. NDE finds the flaw in this weld; only the PQR proves the parameters behind it are sound.

Who is qualified to sign

AWS runs a well-defined certification ladder on its education and certification pages: Certified Welding Inspector (CWI), Senior CWI (SCWI), Certified Welding Supervisor (CWS), Certified Welding Educator (CWE), Certified Welding Engineer (CWEng) and Certified Robotic Arc Welding (CRAW), plus WPQ and WPQ endorsement programmes. Code compliance is a discipline, not a mood.

How to read a real WPS form

Pick up any shop WPS and look for these fields in order:

• Base metal specification and thickness range
• Process (SMAW, GMAW, FCAW, GTAW, SAW)
• Filler metal classification, plus backing or wash material
• Positions qualified
• Preheat and interpass temperature, minimum and maximum
• Shielding gas type and flow rate
• Core parameters: amperage, voltage, travel speed, filler size
• Technique: stringer or weave, electrode angle, cleaning between passes
• Required test results and the supporting PQR reference

If the first item is missing, the sheet is not a procedure. If the PQR reference is missing, it is an unproven procedure. And if it references a code you cannot name from memory, bring in someone who can, or read the career and standards overview for professional welding to see how the qualification tiers actually work.

Setting the Parameters: Joint Prep, Filler Metal, Preheat, Gas and Technique

Frameworks and qualification paperwork are the easy part. This is where a procedure earns its keep, because these are the settings a welder touches on every joint. Get them right and the weld repeats itself. Get them wrong and no amount of qualified paperwork saves the part.

Joint preparation and fit-up

Joint design comes off the drawing, but preparation happens on the floor. The four common configurations are butt, lap, tee and corner, and each has its own prep logic. A butt joint means managing three numbers: groove angle (how far the bevel opens), root face (the flat land the root pass must melt through) and root gap (the space between the two edges). A square butt prepared with a gap of roughly 1.6 to 3.2 mm (about 1/16 to 1/8 in) welds cleanly in SMAW and GMAW. Too tight and the arc cannot reach the root, so you get lack of fusion. Too wide and it blows through, leaving a burnt root and a weak centre.

Fit-up tolerance is the biggest single predictor of fusion problems, and it is a measurement, not an opinion. Gauge it before tacking, not after. Keep tacks small and sound, and place them where they will not be ground out. A cracked tack hidden under a later pass is a defect waiting to surface.

Clean to bright metal before welding: rust, mill scale, paint, oils and grease, from the joint faces and the surrounding area. Aluminium needs a solvent clean and oxide removal even more, and a proper aluminium cleaning routine saves far more time than chasing porosity later. For stainless the rule is absolute: dedicated wire brushes, dedicated grinding wheels, dedicated work area. Iron contamination picked up from a carbon steel wheel leaves rust streaks on the part weeks after it left the shop.

Filler metal selection

Match the filler to the base metal in two ways: strength and alloy system. A 60 ksi electrode on 50 ksi plate wastes money and invites a code question. An alloy-system mismatch is worse, because you can weld it and still end up with corrosion or cracking.

On carbon steel, low-hydrogen classifications such as E7018 and the E70xx-18 family generally beat cellulose types like E6010 and E6011 for restrained joints, higher-strength steels and any joint where a code calls for controlled diffusible hydrogen. Cellulose electrodes remain excellent for field work, general fabrication and all-position convenience, and our all-position rod guide covers when to use them. For GMAW, ER70S-6 and ER70S-5 solid wire are the workhorses: ER70S-6 is the more ductile, better-flowing option, ER70S-5 a slightly more efficient deposit for larger fillets.

Stainless typically calls for 308L (matching 304/304L) and 309L for dissimilar or higher-temperature joints. Aluminium uses ER4045, a silicon alloy that is filler-rich and easy to weld, and ER5356, an aluminium-magnesium alloy with higher strength and better ductility, often preferred where the part will be heat treated afterwards. Our aluminium MIG guide walks through the gas and wire combinations in more detail.

Shielding gas

C25, roughly 75% argon and 25% carbon dioxide, is the general-purpose shielding gas for carbon steel: stable arc, good penetration, forgiving of small parameter changes. For stainless and aluminium, 100% argon is standard, with a small oxygen addition often used for stainless MIG to stabilise the arc.

Two failure modes are worth memorising. Pure argon on carbon steel starves the arc of ionisation, so the arc hunts and the deposit goes porous. A CO2-heavy blend on stainless promotes oxidation, discolouration and a heavy oxide layer that ruins corrosion performance. Gas selection also ties into storage and handling, covered in our welding gas and cylinder guide, and OSHA requires that filler metal containers carry a notice not to use the product in areas without adequate ventilation.

Preheat, interpass temperature and PWHT

Codes tabulate minimum preheat by material thickness and carbon content, so a procedure needs the carbon equivalent and the thickness range before preheat can be specified. Higher carbon content, thicker plate and higher restraint all push the minimum up.

Root passes and GTAW work need more attention than a hot pass in the middle of a fillet. A root pass is small, the section is thin, and a cold start on a large heat sink eats the heat you thought you had. Interpass temperature limits then control heat-affected zone grain growth, and staying under the limit keeps the coarse-grained zone from softening or embrittling. Where a code requires post-weld heat treatment, it becomes part of the procedure itself, with specified heating rates, soak temperatures, thermocouple spacing and hold times, and ASME B31.3 covers those requirements in detail for process piping.

Technique and the worked example

Technique variables belong on the sheet too: stringer or weave beads, work angle, travel angle (usually a 10 to 15 degree drag), push or pull, weaving speed, dwell at the toes of a fillet, back-stepping, bead sequence for distortion control, and slag removal between passes in SMAW and FCAW. Dwell and weaving are the quiet killers, because pausing at the edges of a wide bead soaks heat into the toes and can undercut or overlap the adjacent pass.

Now the numbers showing why travel speed matters more than most people think. Heat input per unit length is volts multiplied by amps, times 60, divided by travel speed in mm/min, divided by 1000. At 24 V and 200 A:

Travel speed	Arc energy (before efficiency factor)
150 mm/min	about 1.92 kJ/mm
220 mm/min	about 1.31 kJ/mm

Raise the travel speed by about 47% at the same voltage and current and you cut the energy going into the joint by roughly a third. That is the difference between a wide, soft HAZ and a tighter one, and between a pass that distorts the bracket and one that does not. Change the same joint to a 16 V setting, or a 180 A current, and the calculation shifts again. That is why the sheet, not the habit, has to be the reference.

One last note on stainless: the dedicated-tool rule is a habit worth building now, because contamination cannot be welded out later. TIG punishes any contamination, which is why sectors like aerospace push cleanliness so hard, as our aerospace TIG welding guide explains in more detail.

Safety: Fumes, Heat, Fire, Electricity and Confined Spaces

A welding procedure that ignores safety is a habit with paperwork attached. Codes insist the controls get written down (ventilation, fire watch, PPE, confined space entry) because once a job leaves the shop floor nobody remembers how the last one went. Give that section of your WPS the same care as the amperage table.

Fumes: what is actually in the plume

Welding fume is not smoke, and it is certainly not “just steam.” It is a fine mixture of metal oxide particles the lungs absorb readily. The NIOSH welding hazards overview notes that nearly all welding fume contains manganese, and manganese shows up in almost every common process. It is the quiet hazard: NIOSH states prolonged exposure to manganese above 1 mg/m³ may lead to a Parkinsonian syndrome known as manganism, and also documents welder’s anthrax as an occupational disease among metalworkers.

Manganese exposure limit	Value
OSHA PEL	5 mg/m³ (ceiling)
NIOSH REL (TWA)	1 mg/m³
NIOSH REL (STEL)	3 mg/m³
NIOSH IDLH	500 mg/m³
ACGIH TLV, respirable fraction	0.02 mg/m³ (TWA)
ACGIH TLV, inhalable fraction	0.1 mg/m³ (TWA)

Stainless adds a different toxic hazard. OSHA’s hexavalent chromium page states that Cr(VI) causes cancer and targets the respiratory system, kidneys, liver, skin and eyes, and identifies welding and other hot work on stainless and other chromium-containing metals as a major source of worker exposure. You cannot see or smell it, and it settles as hexavalent chromium dust on nearby surfaces.

Consumable choice is partly a fume-control decision, which is why a reference such as our guide to alloy steel welding electrode selection, use and safety is worth keeping in the same folder as your WPS.

Ventilation: general plus local exhaust

OSHA 29 CFR 1910.252(c) requires fume, gas and dust concentrations to be kept below maximum allowable concentrations, and requires filler metal containers to carry the notice “Do not use in areas without adequate ventilation.” General ventilation dilutes the plume; local exhaust removes it. Position the extraction arm about a hand’s width from the arc and move it as the job moves. A fume arm parked at the far end of a 20-foot table is decoration. Gas cylinder storage, regulators and chain-up practice are covered in our guide to air gas welding supply, cylinders and safety.

Heat: welding is radiant heat work

An arc throws intense radiant heat at the welder and nearby workers, and a full arc day in a lined jacket is a heat-illness risk even in air-conditioned shops. OSHA’s heat guidance identifies wet-bulb globe temperature (WBGT) as the most accurate way to measure environmental heat impact on body temperature, and promotes “water, rest, shade” as both prevention and treatment. Build acclimatisation into the schedule for new and returning workers, and set hours, rest and hydration in the procedure instead of leaving them to individual judgement. OSHA’s current National Emphasis Program on outdoor and indoor heat hazards is Directive CPL 03-00-024 (April 10, 2026), so expect enforcement attention in peak season.

Fire: the 35 ft rule and the fire watch

1910.252(a)(2)(iii) requires fire watchers where appreciable combustible material is within 35 feet (10.7 m) of the work, and requires a fire watch be maintained for at least half an hour after welding or cutting is completed. Move combustibles out of that 35 ft radius, or protect them with fire blankets and keep the area clear. Never weld metal that still carries combustible coverings such as paint, paper, cloth or tape. NFPA 51B is incorporated by reference into the OSHA standard and adds detailed preheat requirements for adjacent combustible materials.

Electricity: the return path is the dangerous part

Per 1910.254, chains, wire ropes, cranes, hoists and elevators shall not be used to carry welding current, and magnetic work clamps must be freed of adherent spatter before use. Ground machine frames, keep work leads out of walkways, make no splices within 10 feet of the electrode holder, and never use a pipe, conduit or structural member as the return path. Open-circuit voltage limits are 80 V AC and 100 V DC, which is one reason inverter machines are set up by trained people rather than by whoever picks up the leads.

Confined spaces

In tanks, vessels and hoppers, leave welding machines and gas cylinders outside the space, post an attendant with a preplanned rescue procedure ready to summon help, remove the electrode from the holder when work stops, and mark hot metal after completion so no one walks into it. These steps sit in Subpart Q alongside 1910.253 and 1910.254, and your procedure should reference the confined space permit and ventilation plan rather than leave it to the crew on the day.

Eye protection: shade numbers from 1910.252(b)(2)(ii)(H)

Process and electrode diameter	Filter shade
SMAW, 1/16-, 3/32-, 1/8- and 5/32-inch electrodes	10
SMAW, 3/16- and 1/4-inch electrodes	12
SMAW, 5/16- and 3/8-inch electrodes	14
Gas-shielded arc welding of ferrous metals	12

OSHA presents this table as a guide that may be varied to suit individual needs, but write the chosen shade into the setup sheet so every welder starts from the same number.

Common Mistakes and How to Troubleshoot Weld Defects

A cracked fillet rarely starts with bad steel or a bad electrode. It starts with a drift nobody wrote down: travel speed crept up, the arc got longer, a gust of wind crossed the joint, and now there is a porosity cluster to grind out.

Treat a failed weld as a data point, not a verdict on the welder. Know what each defect looks like, where it forms and which parameter it points to, then work backward to the setting that produced it.

The Four Defects You Will See Most Often

Defect	What it looks like	Likely causes	Corrective actions
Undercut	Groove or gouge along the bead toe where the arc dragged on the joint side	Excess travel speed, wrong work angle, long arc, excess amperage, poor fit-up	Reduce travel speed, use about a 10-degree drag angle, correct work angle, grind to sound metal and restart
Porosity	Gas pockets or pitting revealed when the bead is cut open, often clustered at the start or stop	Wet or contaminated base metal, wrong shielding gas or low flow, drafts and wind, excess travel speed, dirty wire, damp electrodes	Clean to bright metal, check flow and leaks, screen from wind, dry consumables per the manufacturer
Lack of fusion / cold lap	Unbonded bead sides with rounded unmelted edges visible after grinding	Not enough heat, bead on the wrong side of the joint, travel speed too fast, wrong electrode angle, inadequate root gap	Raise heat input, correct work angle and bead placement, open root gap, grind out and re-weld
Slag inclusion	Dark irregular pockets trapped in the weld, flagged by magnetic particle or ultrasonic testing	Poor interpass cleaning, wrong electrode angle, wandering the bead, multi-pass work without slag removal	Remove all slag between passes, chip and brush, keep the electrode angle consistent, plan passes so each cleans the previous

Slag deserves special mention in stick work. With SMAW, every pass leaves a slag blanket that must be chipped and brushed before the next pass, and skipping that is the most common cause of inclusions. New to stick? The advantages of stick welding explained cover the cleaning habits that keep SMAW forgiving in the field.

Cracking: Know Which Kind You Are Looking At

Cracks are the defect most likely to end a job, and they split into two families that look similar but behave differently. Hot cracking responds to geometry and restraint, cold cracking to hydrogen and heat control, so using the wrong fix wastes time.

	Hot cracking	Cold cracking
When it appears	While the weld is still hot as it solidifies	Delayed, often hours after the weld cools
Where	Along the bead centreline or in the toe	In the heat affected zone, at the toe or in parent metal nearby
Typical conditions	High sulphur or nickel, wide deep beads, high restraint, poor sequencing	Hydrogen-assisted: diffusible hydrogen, susceptible microstructure, residual stress
Response	Reduce restraint, narrower beads, better sequencing, lower sulphur	Low-hydrogen consumables, control preheat and interpass temperature, manage heat input, sequence properly

Distortion and Residual Stress

Distortion is a geometry problem rather than a defect, but it is the failure that most often sends a weld back. It comes from high heat input, unbalanced sequencing, long welds and poor fixturing, and slowing a long weld makes it worse by concentrating heat in one area. The remedies mirror those causes:

• Back-stepping so heat spreads rather than piling at one end of the seam.
• Balanced sequences welding opposing sides alternately.
• Strong fixturing against the movement heat will cause.
• Pre-cambering and joint offsets to land the part in tolerance.

A Practical Debugging Sequence

When a weld fails, check the parameter sheet against reality before blaming anyone:

1. Measure actual travel speed. Time a pass of known bead length; most crews guess optimistically.
2. Check arc length against the voltage band on the sheet; a long arc changes heat input.
3. Check gas flow and leaks in the hose, gun and regulator, and verify amperage at the machine under load, not the dial setting of an idle machine.
4. Inspect consumables and base metal, then compare with the procedure sheet.

What Inspection Can and Cannot Tell You

No single test proves the procedure is right. Each method answers a different question:

• Visual inspection catches undercut, surface cracks, profile, size and alignment.
• Magnetic particle testing finds surface and near-surface flaws in ferromagnetic materials.
• Liquid penetrant testing detects fine surface-breaking defects on non-porous materials.
• Radiography reveals internal volumetric defects such as porosity and inclusions.
• Ultrasonic testing detects internal planar and volumetric flaws, the method of choice in thicker material.

These methods share standardised vocabulary and acceptance criteria in AWS A3.0M/A3.0:2025, the standard for nondestructive examination terms, definitions and acceptance criteria across welding codes. A passing NDT report tells you the joint meets those criteria, not that the procedure is right, that the consumables were specified, or that the next weld will be identical.

Fume Spikes While You Debug

Chasing defects means grinding, rewelding and hot passes over dirty metal, the worst time for fume exposure. OSHA 29 CFR 1910.252(c) requires ventilation to keep toxic fumes, gases and dusts below maximum allowable concentrations, and fume generation peaks on the first pass of a joint. The NIOSH welding topic hub notes the heaviest fume also occurs in vertical-up welding, so keep local exhaust near the arc while grinding and rewelding in the same bay. On thinner material, check the all position welding rod guide to confirm the consumable matches the position first.

I’ll rewrite this section to fit the word count while keeping the heading, facts, and all links intact.

Building Your Own Procedure: A Practical Workflow You Can Repeat

Writing a welding procedure sounds bureaucratic until you watch a shop live without one. Then you see three welders making the same bracket three different ways, and complaints start rolling in about the third shift’s work. A procedure is simply the fix for that: one document everybody follows, so the same joint comes out the same way on Monday morning and Friday night.

The workflow below works whether you build pressure piping under code or repair a loader bucket in a farm shop. Only the amount of paperwork on top changes.

The Ten Steps, In Order

1. Define the joint and the design intent. Write down the material specification, the full thickness range you actually see on the job, the load the joint carries, service temperature, corrosion environment, and any client or designer requirements. If the drawing says 10 mm but you have seen 6, 10 and 14 mm plate in the same assembly, the procedure covers the range, not just the nominal.
2. Identify the governing code. Name the applicable standard and any client, insurer or inspection agency requirement sitting on top of it. Structural steel, pressure piping, bridges, tanks and aluminium all have their own qualification logic.
3. Select the process and consumable. Process choice follows from joint geometry, position, material, environment and the deposition rate you need. Match the filler classification to the base metal and to what the code allows.
4. Set the parameter set. Amperage, voltage, travel speed, filler diameter, shielding gas and flow rate. Then calculate the resulting heat input and check it against the limit for that material and thickness.
5. Run the procedure qualification test. Make test welds covering the worst case in your range: thickest material, hardest position, lowest preheat condition. This produces the PQR, the record proving those parameters work.
6. Write the WPS from the qualified parameters. Not the other way round. The WPS is a transcription of proven settings, not a wish list.
7. Confirm each welder’s WPQ. Every person making that weld needs their own performance qualification for that procedure. A qualified procedure does not cover the welder.
8. Publish a shop work instruction and a one-page setup sheet. The setup sheet goes at the machine, not in an office drawer. Amperage, voltage, wire size, gas, travel speed, torch angle.
9. Define the inspection plan and hold points. Who inspects, what method, what acceptance criteria, and where work stops until a hold point is released.
10. Control revisions and records. Know in advance what triggers a requalification.

Revision Triggers Worth Writing Down

Triggers that send a procedure back for requalification include a change of base metal specification, a move outside the qualified thickness range, a new welding position, a different consumable classification, or a change of shielding gas or flow rate. A new consumable lot does not normally require requalification, but recording lot numbers and results is good practice for traceability.

Treat equipment changes carefully too. Swapping a constant-current machine for a different power source means checking that the parameters still hold. OSHA 29 CFR 1910.254(d)(9) is explicit on the wider point: operators should report any equipment defect or safety hazard, and equipment should not be used until its safety is assured, with repairs made only by qualified personnel. A machine that behaves oddly is a procedure defect, not just a maintenance ticket.

A Sample Parameter Sheet (A Starting Template, Not a Code Document)

The table below is a realistic starting point for a structural fillet weld, a template you qualify and adjust for your own shop. Do not weld from it because it appears in a table.

Item	Example value
Application	Structural steel fillet weld, shop
Base metal	Carbon steel, 6 to 12 mm
Process	SMAW
Filler metal	E7018, 3.2 mm
Position	Horizontal fillet (qualified further for vertical)
Preheat / interpass	Per code table for material and thickness; verify by contact thermometer
Current	115 to 130 A, DCEP
Voltage	22 to 24 V
Travel speed	Approximately 180 mm/min
Arc length	Target 2 to 3 mm, roughly a pencil-width gap
Technique	Stringer beads, slight drag angle
Cleaning	Grind to bright metal before each pass; remove all slag
Heat input limit	Maximum value per governing code, calculated from qualified settings

Where Documentation Stops and Common Sense Starts

Not every weld needs a PQR. A repair shop, a hobbyist or a farm equipment operation will never see an AWS inspector walk in. But a written internal standard still pays, for different reasons: consistency across shifts, one method instead of four, and a baseline you can teach a new hire from. Shops that later take on code work usually already have the discipline. Shops that do not learn it the expensive way.

Automation: Real Gains, Real Limits

Robotic arc welding delivers genuine repeatability and cycle time, and the growth is real enough that AWS now offers a Certified Robotic Arc Welding (CRAW) credential alongside the Certified Welding Inspector (CWI) and Senior CWI certifications and a Welding Coordinator, QA endorsement. But a robot will not rescue a bad joint. It demands good fixture design, joint accessibility, consistent part presentation and reliable seam tracking. Bad fit-up plus a robot equals a fast way to make the same bad part.

Equipment That Actually Earns Its Place

A few upgrades earn their keep in procedure control. Local fume extraction arms (see our welding equipment guide) turn a poor habit into a controlled exposure. Stable wire feeders remove spatter-driven parameter drift. Inverter power sources with arc control and preheat assist make the settings on the sheet easier to hit consistently. Digital calipers and thermocouples let you verify preheat rather than guess. Each helps, none replaces the discipline.

Conclusion: What to Take Back to the Shop

An electric arc welding procedure is a document. Not a rule of thumb, not a memory, not a phrase somebody learned twenty years ago and never wrote down. It is a written, repeatable set of instructions that turns what happens at the machine from a personal habit into a controlled process.

Every procedure here, from a one-off field repair to a code pressure weld, has the same four parts.

• Process. What you are welding with: SMAW, GMAW, FCAW, GTAW or SAW, plus the consumables and shielding that go with it.
• Parameters. The numbers that shape the bead: amperage, voltage, travel speed, electrode size, preheat and interpass temperature, gas and flow rate.
• Qualification. Test results proving those parameters work for your base metal, filler, position and thickness, and that the welder can weld to them.
• Verification. The inspection plan, acceptance criteria and records showing the weld is what the procedure said it would be.

The technical takeaways

• Arc length and travel speed drift first. They wander off the sheet more than any other variable and quietly wreck a bead. Measure travel speed with a stopwatch and write the arc length target in millimetres, not “about a fist”.
• Process choice is a compromise. Deposition rate against position, environment against material, shop speed against clean finish. There is no best process, only a defensible one for the joint in front of you. It is still worth reading why SMAW still wins on a lot of field work.
• Preheat, interpass temperature and hydrogen control cracking. That trio, not amperage, separates a sound weld from a delayed failure. No preheat provision on a thick or high-carbon joint is a procedure waiting to crack.

And the part people skip: a qualified procedure without a qualified welder and an inspection plan is incomplete. All three have to exist, and all three have to be current.

The safety numbers worth memorising

• Manganese. OSHA’s permissible exposure limit is 5 mg/m³ as a ceiling; NIOSH’s recommended limit is far tighter at 1 mg/m³ as an 8-hour average and 3 mg/m³ short-term. Fume peaks on the first pass and in vertical-up.
• Hexavalent chromium. A known carcinogen, generated when welding stainless and other chromium-bearing alloys. It affects the respiratory system, kidneys, liver, skin and eyes, so stainless work needs real local exhaust, not a window open across the shop. OSHA’s hexavalent chromium resources set out the exposure limits and controls.
• Fire. OSHA 1910.252(a)(2)(vii) requires that, where practicable, all combustibles be relocated at least 35 feet (10.7 m) from the work site, and the fire watch continues for 30 minutes after the last arc is struck.
• Electricity. OSHA 1910.254(b)(3) caps open-circuit voltage at 80 V for AC manual arc welding and 100 V for DC manual arc welding.
• Heat. Water, rest and shade, tracked with wet-bulb globe temperature (WBGT), which OSHA’s heat guidance calls the most accurate measure of workplace heat stress.
• Respirators. They only work inside a written programme with medical evaluation, fit testing and training, as OSHA’s respiratory protection overview explains. An un-fitted respirator is decoration.

Ten things to do tomorrow

The last item compounds. The rest takes an afternoon; the written record turns a good weld into a repeatable one.

To go deeper, the AWS codes and standards library holds the governing documents, including D1.1 for structural steel, and the AWS education and certification programmes lead to recognised welder, inspector and engineer credentials. OSHA’s Subpart Q welding standards are free to read, and more readable than most people expect.

Welding is a trade where skill is personal but quality is public. The best welders in any shop are the ones who write down what works, because their procedures make the next good weld repeatable, even when they are not the one holding the electrode.

Frequently Asked Questions

What is the difference between a welding procedure and a Welding Procedure Specification (WPS)?

A welding procedure is the overall concept — how a particular weld is going to be made. The WPS is the written document that captures it in a format the code recognises: base metal, thickness range, process, filler metal, positions, preheat and interpass temperature, gas, amperage, voltage, travel speed and technique. The PQR is the supporting test data proving the parameters in that WPS actually produce an acceptable weld.

Do I really need a qualified procedure for a garage or farm project?

Not legally, in most cases — codes and contract specifications apply to regulated work such as pressure piping, structural steel, bridges and tanks. But a written internal standard still pays off: it stops drift between shifts, gives new welders a starting baseline, and makes it obvious when something is wrong with the joint or the consumable. Write the simple version: process, consumable, amperage, voltage, travel speed, arc length, cleaning steps and inspection.

Which arc welding process is easiest for a beginner to learn?

SMAW (stick) is often recommended because the machine is simple, there is no gas bottle to manage, and the electrode itself is a small consumable lesson in metallurgy. GMAW (MIG) is faster and easier to feed continuously, but it hides more variables and punishes dirty or out-of-position work. Many shops teach stick first, then move to GMAW for production and FCAW or GTAW for specialised work.

How do I calculate heat input for a weld?

Use heat input (kJ/mm) = (voltage × amperage × 60) ÷ travel speed in mm/min ÷ 1000. At 24 V, 200 A and a 150 mm/min travel speed that gives about 1.92 kJ/mm. Multiply by an arc efficiency factor (roughly 0.8 for shielded processes is a commonly cited approximation) to estimate net heat input to the base metal, and always check the governing code for the heat input limits it actually enforces.

What is a PQR and how is it different from a WPQ?

The PQR (Welding Procedure Qualification Record) qualifies the procedure — it shows that a specific set of parameters on a specific base metal, filler metal, position and thickness range produced a weld that passed the code’s test requirements. The WPQ (Welder Performance Qualification) qualifies the welder — it shows that an individual person can make a compliant weld to that procedure. A shop can have a perfect WPS and still be non-compliant if the welder is not qualified to it.

Does welding stainless steel need extra safety precautions?

Yes. Welding stainless and other chromium-bearing alloy steels generates hexavalent chromium, which OSHA states is known to cause cancer and affects the respiratory system, kidneys, liver, skin and eyes. That means aggressive local exhaust ventilation, appropriate respiratory protection under a written program, and dedicated stainless grinding tools and brushes to avoid iron contamination.

What causes undercut, and how do I fix it?

Undercut is a groove melted into the base metal at the toe of the weld. The usual causes are excessive travel speed, too much amperage, holding the arc too long, an incorrect work angle, and poor fit-up that forces the electrode to reach past the joint. Fixes include slowing the travel speed, matching amperage to electrode diameter, keeping a consistent arc length and 10-degree drag angle, and grinding back to sound metal before depositing additional passes.

How hot does welding get, and do I need to worry about heat illness?

Yes. Arc welding combines radiant heat from the arc with the heat of a molten metal, and OSHA lists iron and steel mills and foundries among industries where workers suffer heat-related illness. OSHA identifies wet-bulb globe temperature (WBGT) as the most accurate way to assess heat stress, and promotes water, rest and shade along with acclimatisation for new workers.

Which helmet shade should I use for stick welding?

OSHA’s shade guide in 29 CFR 1910.252(b)(2)(ii)(H) lists shade 10 for SMAW with 1/16-, 3/32-, 1/8- and 5/32-inch electrodes, shade 12 for 3/16- and 1/4-inch electrodes, and shade 14 for 5/16- and 3/8-inch electrodes; gas-shielded arc welding of ferrous metals is listed at shade 12. OSHA notes these are a guide that may be varied to suit the individual, so start a shade darker than you think you need and adjust.

What is the biggest cause of weld porosity?

In most shop cases it is contaminated or wet base metal, not the machine. Rust, mill scale, paint, oil and moisture all trap gas in the weld pool. Other frequent causes are incorrect shielding gas or inadequate flow rate, drafts blowing the shielding away, dirty consumables, and excessive travel speed. Clean back to bright metal, verify gas flow and leaks, shield the joint from wind, and check the wire and electrode storage.