Types of Welding Beads: Stringer, Weave & Patterns Guide

A first-year apprentice once laid what he proudly called a ‘stack of dimes’ on a structural bracket — wide, shiny, and completely rejected by the inspector for excessive weave width and undercut at the toes. Beads don’t lie: everything about your hand speed, arc length, travel angle and heat control is written on the surface of the metal, and knowing which bead type belongs in which joint is the difference between a weld that passes and a weld that gets ground out.

What Is a Welding Bead? (And Why Bead Type Matters More Than You Think)

Ask ten new welders what a bead is and you’ll usually get a shrug or a vague “the line of metal you weld.” That answer is close, but it hides the detail that separates a welder who passes inspection from one who spends Friday grinding out rejects. A weld bead is the visible line or deposit of fused filler and base metal produced by a single welding pass across the joint. One pass in, one bead out. The bead is the physical record of that pass: its width, height, penetration, ripple spacing and tie-in at the edges are all written by your hand speed, arc length, travel angle and heat control.

That definition matters because the words around it are often used interchangeably when they shouldn’t be.

Bead vs. Pass vs. Pool vs. Joint

• Weld pool (crater/puddle): the small, molten zone of base and filler metal directly under the arc at any given moment. It moves; the bead is what it leaves behind.
• Weld pass: one continuous movement of the electrode or torch along the joint. Each pass normally deposits one bead, though a woven pass can lay several overlapping ripples across a wide face.
• Weld bead: the resulting deposit itself, measured and inspected as geometry — face, toes, throat, reinforcement.
• Weld joint: the whole assembly being joined — the groove, fillet, lap or butt configuration — which may contain many beads across many passes.

In short: the pool is the process, the pass is the action, the bead is the result, and the joint is the job.

Why Bead Selection Decides Whether You Pass or Fail

Bead profile isn’t cosmetic. The Iowa DOT standard specification IM 558 makes profile an acceptance item because width, height (reinforcement), penetration depth and ripple spacing directly affect how the weld behaves under load. A bead that is too tall concentrates stress at its toes; one that is too wide dumps excess heat into the plate; one that is too thin and cold never fuses into the sidewall.

Choose the wrong bead type and the problems compound:

• Penetration: a narrow stringer concentrates the arc and drives deeper; a wide weave spreads the same energy across a broad face, reducing depth per unit width.
• Heat input: slow, wide oscillations raise total heat input, coarsening grain in the heat-affected zone and increasing distortion risk on thin sections.
• Mechanical properties: coarser HAZ grain and higher heat input can reduce toughness — a nuance the AWS welding-crack literature links to solidification cracking patterns.
• Inspectability: uneven ripples, sagging toes and excessive crown make visual and ultrasonic examination harder, and invite rejection before the NDE truck even arrives.

Poor bead profile also causes downstream defects: a lumpy, concave or misaligned bead leaves valleys that trap slag and create incomplete fusion between the next passes. In other words, today’s ugly root bead becomes tomorrow’s slag inclusion.

The Main Types of Welding Beads

Welding beads are usually classified on two axes:

1. By motion: a stringer bead is run straight ahead with little or no side-to-side movement, while a weave bead is oscillated across the joint to build width. These are the two primary categories, and most code discussion orbits around them.
2. By function in a multipass weld: the root bead (first pass in the joint), the hot pass (cleaning and strengthening pass over the root), the fill beads (building throat thickness) and the cap or cover bead (final appearance and profile).

Within weaving sits a family of named patterns — zigzag, crescent, figure-eight, triangle, J-weave and stepped or sawtooth — each matched to a joint geometry and position. Whether you run stick, wire or TIG changes the preferred pattern too; a short-circuit MIG bead naturally stacks into fine, evenly spaced ripples, while a stick bead built from a fast-freeze electrode looks coarser. For a practical look at how electrode choice shapes bead behavior, see our All Position Welding Rod Guide.

What Bead Appearance Tells You About Your Technique

Inspectors read beads like a handwriting sample. Uniform, closely spaced ripples signal consistent travel speed and a steady arc length. Smooth, gradual tie-in at the toes means you held the right work angle and paused where you should. Slight convexity without undercut shows balanced heat. Ragged ripples of varying width mean the arc was wandering; a tall, narrow crown means slow travel or too much current; a flat, washed-out bead means too much heat. Acceptance profiles are even codified in the AWS D1.1 groove weld profile criteria.

The takeaway: the bead is feedback. Learn to read it, and you’ll catch and correct your own technique long before the inspector does — and once you can read a bead, choosing the right one for the joint becomes second nature.

Anatomy of a Weld Bead: Ripples, Throat, Toes and Reinforcement

Before you can choose between a stringer and a weave, you have to be able to read a bead. Every bead you lay is a frozen record of what your hands did: travel speed, arc length, work angle and heat control are all written into the metal surface. Inspectors read that record in seconds, and once you learn the vocabulary, so can you.

The Parts of a Bead

A welding bead has five features worth knowing by name. They appear in every procedure specification, inspection report and welding code you will work under.

Feature	What it is	Why it matters
Face	The visible top surface of the bead	Where ripples live; the first thing visual inspection judges
Toes	The edges where the bead ties into the base metal	Notched toes are the classic starting point for fatigue cracks
Throat	The shortest distance from the face to the root of the weld	The load-carrying cross-section of the joint
Root	The deepest point of fusion at the bottom of the bead	Determines penetration and the strength of the joint’s back side
Reinforcement (crown)	Metal deposited above the plane of the joint surface	Some is required; too much creates a stress riser

Reinforcement is not a bonus. Codes cap it because excess crown concentrates stress at the toe, exactly where fatigue cracks begin. Under AWS D1.1, groove weld reinforcement is generally limited to about 1/16 in (1.6 mm) above the base metal surface unless the drawing says otherwise, and undercut is allowed only within tight numeric limits that vary with material thickness and steel type.

How Ripples Form — and What They Reveal

Ripples are solidification lines. As the arc moves on, the trailing edge of the molten puddle cools and freezes in successive small increments, and each freeze front leaves a crescent-shaped line behind it. Because solidification always proceeds from the cooler, already-frozen metal toward the still-liquid center, the ripple lines point backwards, tracing the exact direction the puddle travelled.

Their spacing is a speedometer. Even, closely spaced ripples mean steady travel speed and consistent arc length. Widening gaps mean you sped up; bunched ripples mean you hesitated. Irregular, washed-out ripples usually point to an arc that was too long. In short-circuit MIG the ripples take on the familiar stacked-dime look because each transferred drop freezes as a discrete step, which is why Aluminum MIG Welding: The Complete Practical Guide treats ripple consistency on aluminum as a travel-speed and heat-control exercise.

What a Good Bead Actually Looks Like

• Uniform ripples with consistent spacing and height across the full length.
• A smooth tie-in at the toes — the metal blends into the plate with no visible notch or step.
• Slight convexity — a modest crown, not a bulging rope of metal.
• Consistent width from start to finish, ending in a filled crater rather than a pip.

Excessive convexity is the most common failure, and it is not purely cosmetic. A high crown creates a sharp geometric transition at the weld toe, raising stress concentration there and shortening fatigue life. It usually means travel speed was too slow for the amount of metal being deposited, or current was set too low to let the puddle wet out and flatten. The fix is to balance deposition against travel, not to grind the crown down and hope.

Depth-to-Width Ratio and Centerline Cracking

Shape also governs cracking risk. A deep, narrow bead solidifies from both side walls inward, squeezing the last liquid — and with it, low-melting impurities such as sulfur and phosphorus — into a thin centerline channel. That trapped film tears as the bead contracts, producing a centerline (longitudinal) crack running down the middle of the weld. AWS Inspection Trends covers how these cracks initiate and why the centerline is the vulnerable path.

Procedures therefore favor a bead roughly as wide as it is deep or wider. When a groove is too deep to fill in one pass at a healthy ratio, the answer is multiple passes in layers rather than one oversized bead.

Profile Comes First in Visual Inspection

Visual testing (VT) always starts with profile before any dye penetrant, radiography or ultrasonic work is scheduled. The inspector checks contour, reinforcement height, undercut depth, toe blending and total weld width against the acceptance tables — the AWS D1.1 groove weld profile acceptance criteria are the common reference in structural work. A simple bridge or fillet gauge measures reinforcement and undercut in one pass across the bead.

Surface prep ties into this directly: Aluminum Cleaner for Welding: How to Prep Aluminum Right matters because a bead judged under oxide, soot or spatter is being judged on contamination, not on your technique. Clean the bead, then read it honestly — the geometry will tell you exactly what to change on the next pass.

Stringer Beads: The Straight-Line Foundation of Good Welding

Ask a hundred experienced welders to demonstrate proper technique and most will lay the same thing: a stringer. It is the first bead taught in any welding booth and the standard against which every other bead type gets judged. If your stringers wander, your weaves will be worse, and no amount of side-to-side motion hides an inconsistent hand.

What Actually Makes a Bead a Stringer

A stringer bead is deposited with a straight push or drag motion and little to no lateral oscillation. The arc stays locked in the puddle, the electrode follows the joint line, and the finished bead width comes from electrode diameter, current, travel speed and work angle rather than from swinging the arc side to side. That focused arc is the whole point: all available energy is aimed at one narrow track of base metal instead of smeared across a wider surface.

Four variables decide whether your stringer is credible:

• Travel angle: about 10 to 15 degrees of drag angle is the everyday starting point for stick and flux-cored stringers, held steady from start to finish. Push angles suit some MIG applications, but the angle must stay constant, because drift changes penetration faster than most beginners expect.
• Arc length: roughly the diameter of the electrode, or slightly tighter. A long arc dumps heat into the air, broadens the puddle and invites porosity.
• Work angle: set by the joint geometry, then maintained. Tilting to “chase” the puddle produces asymmetric beads and one-sided undercut.
• Travel speed: steady and matched to puddle size. Ripples record every hesitation your hand makes.

Why Stringers Run Cooler and Bite Deeper

Because the arc dwells in one narrow track instead of sweeping across it, the heat stays concentrated and travels deeper into the joint rather than across the surface. That produces lower heat input per unit length, and Iowa DOT’s welding guidance identifies lower heat input as superior for controlling grain structure and avoiding cracking. Less heat means a narrower heat-affected zone, less coarse grain growth, and a better chance of staying within the toughness requirements of structural codes. It also means less distortion per inch of weld, which matters enormously on thin plate and long fillet runs.

For open roots, the preference becomes absolute. AWS D1.1 and general structural practice strongly favor stringer passes on root and open-root groove welds, because weaving across a keyhole concentrates heat and can cause burn-through on one side while leaving lack of penetration on the other.

The Whip-and-Pause Exception: E6010 and E6011 Roots

There is one important variation. On open roots run with fast-freeze electrodes like E6010 or E6011, many welders use a controlled whip-and-pause motion. The arc advances slightly ahead of the puddle to punch through and establish the keyhole, then returns to rest in the molten pool so deposited metal ties into both walls. The motion is longitudinal, not side to side, so it is still fundamentally a stringer technique. The discipline is in the timing: pause long enough to wet the edges, advance far enough to keep the keyhole open, and never let the arc run ahead of the puddle with nothing molten beneath it. If you are working through stick fundamentals, our Advantages of Stick Welding: Why SMAW Still Wins guide covers where this technique fits in the broader process picture.

When a Stringer Is the Right Choice

• Root passes and open-root grooves, where a narrow bead gives predictable penetration and minimizes burn-through risk.
• Thin material, where a wide weave almost guarantees warping or a hole.
• Vertical-up work, where short stringers stacked on a solid shelf give better control than a wide weave that can sag.
• Multipass capping, since inspectors frequently require stringers on the exposed face of groove welds.
• Out-of-position welding, where gravity punishes a large puddle. Consumable choice matters here, so see our All Position Welding Rod Guide before you strike an arc overhead.

Common Stringer Mistakes and How to Fix Them

• Arcing out of the puddle: whipping too far forward leaves the weld metal behind thin or cold. Shorten the advance and keep the arc end inside the leading edge of the pool.
• Whipping incorrectly: fast advance with a lazy pause creates erratic ripples and uneven penetration. Pause at the leading edge, advance a small increment, repeat.
• Arc length too long: the classic beginner error. Expect a wide, flat, frothy bead with spatter and porosity. Shorten to roughly one electrode diameter.
• Changing travel speed mid-run: ripple spacing tells on you. Slow down consistently, or reposition your body so you never have to reach.
• Skipping crater fill: breaking the arc while the puddle is still full leaves a shrinking crater that cracks. Back up, hold, and fill it first.

Master these habits on bead-on-plate runs before touching a joint. A clean, evenly rippled stringer that ties smoothly into both toes is the clearest proof that your arc length, travel angle and hand speed are all working together.

Weave Beads: Patterns, Motions and When Weaving Is Required

A stringer bead travels in one direction. A weave bead oscillates side to side as it moves, and that single change is the whole idea: by sweeping the arc across the joint, each pass lays down a wider band of metal, so a broad groove face, a wide fillet or a cover pass can be finished in fewer passes than straight stringers would need. The trade-off is real. Weaving adds heat to the plate, widens the heat-affected zone, and turns small timing mistakes into visible defects. With a weave, the question is never just where the puddle goes, it is how long it stays in each spot.

The Named Weave Patterns

Welders and procedure sheets use a short, shared vocabulary for weave motions. Most patterns are variations on the same handful of shapes, but each has a job it does better than the rest.

Pattern	Motion	Typical use
Zigzag / straight	Sharp, even side-to-side steps with a brief stop at each limit	Flat and horizontal cover passes, wide but shallow joints
Crescent / semi-circle	Arc swung over the front of the puddle in a shallow C	Fillet caps and cosmetic passes where smooth tie-in matters
Figure-eight	Continuous looping motion with no hard stops	Wide cover passes where heat needs spreading evenly
Triangle	Up one side, across, back down, forming a stack of small shelves	Vertical-up fillets and grooves that fight gravity
J-weave	Hook-shaped swing with a pause at the top of the J	Vertical-up groove welds needing side-wall fusion
Stepped / sawtooth	A series of small, deliberate steps across the joint	Narrow groove fills and thin-edge work needing tight control

The Golden Rule: Pause at the Sides, Move Quickly Across the Center

This is the one weave rule that separates a sound bead from a rejected one. When the arc reaches the edge of the weave, hold it there for a beat so the filler metal ties into the side wall and the toe of the weld. Rush that moment and the arc leaves before the crater is filled, which is exactly how undercut forms along the weld toes. Then travel fast across the middle. Dwell in the center and the metal piles up into an excessive crown that is harder to inspect and puts unnecessary reinforcement where the code does not want it. In practice: slow on the edges, quick through the middle, same rhythm every single time.

When Weaving Is Allowed (and When It Is Not)

Structural procedures do not ban weaving, they bound it. Weaving is the sensible choice when:

• The joint face is wide. A single stringer cannot cover a 25 mm groove face without becoming a thin, wandering line that wanders off center.
• You are running a cover or cap pass. The final layer is about profile and appearance, and a controlled weave produces an even, slightly convex face.
• You are filling a multi-pass groove. Intermediate layers are best built with alternating stringers, but the last layers often need side-to-side motion to tie both walls together.
• You are welding vertical-up on a fillet. A triangle or J-weave builds a small shelf of solidified metal that supports the puddle against gravity. Pausing at the top of each triangle lets the leading edge freeze before the next step up. For the rod or wire that makes this motion possible out of position, see our All Position Welding Rod Guide.

Where weaving does not belong: the root pass on a narrow gap, thin sheet where heat control is everything, and any joint where the procedure specifically calls for stringers only. Wide, slow weaves on root or thin sections are a classic route to burn-through and coarse grain in the heat-affected zone. Aluminum makes the point even sharper, since the puddle stays fluid longer and every extra second of arc time shows; the Aluminum MIG Welding: The Complete Practical Guide covers how tight, disciplined weaves behave on that alloy.

Master the rhythm first on plate beads laid side by side, keep the pauses even, and the weave becomes what it should be: a widening tool for joints that need one, not a substitute for puddle control.

Stringer vs Weave: Side-by-Side Comparison and Code Limits

Ask ten welders whether a stringer or a weave is stronger and you will get ten confident answers, all starting with “everyone knows.” The more useful answer is that neither technique is universally better. Stringers and weaves move heat, metal and risk in different ways, and the right choice depends on the joint, the welding position, the applicable code and the procedure you are working to.

Stringer vs Weave at a Glance

Factor	Stringer bead	Weave bead
Heat input	Lower for a given setting and travel speed	Higher, because the arc dwells longer per inch of travel
Deposition rate	Moderate, one puddle width per pass	Higher, one pass covers far more area
Penetration	Deeper and more concentrated	Shallower and spread wider
Bead width	Narrow, roughly one electrode or wire width	Wide, limited by technique and code limits
Distortion risk	Lower, shrinkage stays balanced	Higher when the weave stays wide and hot
Inspectability	Easy to read, ripples expose travel consistency	Toes hide flaws, undercut shows up late
Skill demand	Steady arc length and travel speed	Adds timing: pause at the sides, move fast across the middle
Best fit	Root passes, thin stock, out-of-position work, multipass caps	Wide joints, cover passes, vertical-up fillets

The “Stringers Are Always Stronger” Claim

This one gets repeated so often that it has hardened into a slogan. There is real science behind it, but it is a rule of thumb, not a law.

What actually governs strength is heat input, which is why inspectors and engineers calculate it rather than guess it. The standard form used in DOT and AWS references is:

A stringer keeps that number low: the arc sits in one narrow channel and moves forward. A wide weave keeps the arc in the same general area much longer, and pausing at the toes to fuse them pushes it higher still. Elevated heat input slows cooling, which can grow coarse grains in the heat-affected zone and, in some steels, measurably reduce toughness. Higher heat input is also linked to a greater tendency toward solidification and reheat cracking, which is why AWS inspection commentary on weld cracks treats heat input control as a first-line defense. On heat-sensitive aluminum work, the same effect shows up as softening in the HAZ, a concern covered in our Aluminum MIG Welding: The Complete Practical Guide.

The nuance: a stringer run with a long arc and a crawling travel speed can generate more heat input than a tight, fast weave. Technique quality, not the label, decides the outcome. And a stick-welder running stringers on a heavy root still has to manage puddle size and travel angle, because poor technique on a stringer produces poor welds just as reliably as poor technique on a weave.

What AWS D1.1 Table 5.1 Actually Requires

The code draws a hard line that surprises a lot of welders. Under AWS D1.1, Table 5.1 governs maximum weave width, and when the exposed weld-face width of the next layer would be 1.0 in (25 mm) or greater, the split-layer technique is required.

Split-layer welding (also called layer welding) means you build that wide face from two or more narrower passes tied into each other instead of one fat weave. The payoffs are practical:

• Each pass stays narrow, so heat input per inch drops.
• Toes get properly fused instead of being painted over by a wide crown.
• Undercut and trapped slag become far less likely.
• The finished profile stays closer to the acceptance criteria inspectors check, which we break down in AWS D1.1 groove weld profile criteria.

Who Decides: You or the WPS?

Neither. The welding procedure specification, backed by a qualified procedure qualification record, states whether stringer or weave technique is permitted for each pass. Some procedures allow weaving within a stated width, others prohibit it outright, and a few require it for cover passes. Following a technique your WPS does not permit turns an otherwise sound weld into a documentation failure, no matter how good it looks. When the procedure calls for stringers, run stringers; when it allows a weave, stay inside the width limit and keep the toe pauses crisp. Bead appearance tells the story of your technique, but paperwork decides whether the weld ships.

Beads by Function: Root, Hot, Fill and Cap Passes

Ask a welder what kind of bead they are running and you will usually hear “stringer” or “weave.” Ask a welding inspector the same question and you will get a different answer entirely: root, hot, fill or cap. That second way of thinking is about the job each bead performs inside a multipass joint, and it is the language used on procedure sheets, weld maps and inspection reports. The motion you use matters, but the role you play in the sequence matters more.

The Root Bead: Where the Weld Is Won or Lost

The root bead is the first line of metal deposited into the bottom of the joint. Its job is not to look good or to fill anything. It must establish penetration into both members, tie the edges together, and hold alignment while the rest of the joint is built on top of it. Because it fuses the sharpest geometry and is pulled by shrinkage forces from every direction, it is the most vulnerable bead in the entire weld. AWS crack guidance identifies the first layer of a multipass weld as where cracking is most likely to initiate, which is why fit-up, tack quality and root technique get more scrutiny than anything else (AWS Inspection Trends crack analysis).

Root beads are almost always small and slow. On open-root pipe and plate, a keyhole technique with a tight arc gives full penetration; on thin sheet, a root stringer run at reduced current avoids burn-through. A root that is too thin, too wide, or fused only on one side cannot be rescued by a beautiful cap. Radiography and ultrasonic testing look straight at it.

The Hot Pass: Cleaning and Locking In the Root

The hot pass follows immediately, usually at slightly higher current and faster travel than the root. In stick and flux-cored welding it burns out slag trapped against the root, washes away any partial fusion at the sidewalls, and turns a delicate, notch-sensitive root into a solid foundation. On pipeline work, skipping the hot pass is a common way to turn trapped flux into a slag inclusion that shows up on the film later. On clean processes like GMAW with solid wire, a separate hot pass is often unnecessary because there is no coating to displace.

Fill Passes: Building the Throat

Fill passes do exactly what the name says: they build the weld throat up to the thickness required by the drawing or code. They are usually run as a series of layered stringers, placed deliberately so each bead fuses into the previous one and into the sidewall, and they stop slightly below the final surface so the cap has room to lay down a controlled profile. This is also where heat management becomes a real discipline, because every layer adds thermal history to the layer beneath it. An electrode chosen for its deposition rate and notch toughness through alloy steel welding electrode selection only delivers those properties if interpass limits are respected.

The Cap Pass: The Only Bead Anyone Sees

The cap, or cover pass, seals the joint and sets its final profile: smooth, evenly rippled, with a slight reinforcement and toes that blend rather than step. It is the bead that meets groove weld acceptance criteria for width, height and undercut, and it is the bead a client, an inspector or a camera actually looks at (AWS D1.1 groove weld profile criteria). Cap passes therefore carry disproportionate reputational weight. The uncomfortable truth is that a glossy cap over a defective root still fails, while a rough-looking root verified by sound methods can pass with full confidence.

Sequencing, Overlap and Interpass Temperature

Three rules keep the stack honest:

• Overlap: each adjacent bead should overlap roughly one-third to one-half of the previous bead’s width. Too little overlap leaves cold, unfused valleys between beads; too much means you are remelting good metal, adding heat and doing nothing for throat size.
• Interpass temperature: the WPS sets a maximum interpass temperature precisely to stop cumulative overheating. Successive beads stacked without letting the joint cool produce coarse grain structure, softened heat-affected zones and higher distortion risk. On aluminum, which gives no color warning, this discipline is even more critical, as covered in our aluminum MIG welding guide.
• Ordering: stagger start and stop points between layers, fill craters fully at every termination, and clean the surface between passes so the next bead starts on sound metal.

Bead	Primary job	Typical technique	Common failure
Root	Penetration, alignment, joint tie-in	Small stringer, tight arc, slow	Line cracks, lack of penetration
Hot	Burn out slag, reinforce root	Faster stringer, higher current	Slag inclusion, undercut
Fill	Build throat thickness	Layered stringers or narrow weaves	Poor sidewall fusion, porosity
Cap	Profile, appearance, reinforcement	Stringer or controlled weave	Undercut, overlap, excess crown

The order never changes: a root that fuses, a hot pass that cleans, fills that build, and a cap that finishes. Get the first bead right and every bead after it has somewhere solid to land.

Bead Types by Process: SMAW, MIG, FCAW, TIG and SAW

A bead is only as good as the process that lays it. The hand motion that makes a clean TIG bead will smear and sag in flux-cored arc welding, and a weave that works on thick plate in flat position will drip overhead. Each process has its own puddle behavior, freezing speed and deposition style, so each favors certain bead types and patterns. Know which bead suits your process and you are halfway to a weld that passes inspection.

SMAW (Stick): Fast-Freeze, Fill-Freeze and Keyhole Root Beads

Shielded metal arc welding gives you the widest vocabulary of bead types because the electrode itself dictates how the puddle freezes. Fast-freeze electrodes such as E6010 and E6011 solidify almost instantly, so they dig a deep, narrow bead with heavy penetration. That characteristic makes E6010 the classic root-pass rod: run with a slight drag angle and a short arc, it punches through the joint and opens a keyhole at the leading edge. Holding that hole open as you travel is the sign of a properly fused root.

Fill-freeze electrodes like E6013 and the low-hydrogen E7018 family freeze more slowly, giving you time to work a wider, flatter bead. E6013 likes a soft arc and a slight weave on thin sheet; E7018 is the workhorse for stringer passes on structural steel in every position. Because stick slag hides what happens underneath, bead-to-bead cleaning matters more here than anywhere else: a trapped film between passes becomes the slag inclusion an inspector flags later. For rod selection see our All Position Welding Rod Guide and Alloy Steel Welding Electrodes coverage, while our Advantages of Stick Welding guide explains why SMAW still dominates field work.

GMAW (MIG): The Stacked-Dime Bead and the Spray Stringer

GMAW bead character changes dramatically with transfer mode. In short-circuit transfer, the wire shorts to the work dozens of times per second, and each freeze leaves a tiny ripple. The result is the famous “stacked dimes” appearance that beginner MIG welders chase. It looks gorgeous and works well on thin material, but each short circuit is a low-heat event, so fusion into the root can suffer if the gun angle or wire speed is off.

Push the voltage up and you enter spray transfer: a fine continuous stream of droplets with a fluid, forceful puddle. Spray favors fast, wide stringer beads on thicker steel, and weaving is usually limited because the puddle is already wide and hot. On aluminum, control gets tighter still since it draws heat away quickly; our Aluminum MIG Welding guide covers the adjustments that keep beads flat instead of washed out.

FCAW (Flux-Cored): Heavy Deposition, Drag Technique

Flux-cored arc welding deposits metal faster than any other manual arc process. Self-shielded wire is almost always run drag (pull), gun at a moderate back angle, so the flux stays over the puddle. Beads come out wide, hot and heavily slagged, so stringers are preferred for structural work and weaves stay narrow. Gouging and back-gouging often pair with FCAW on thick joints, which you can read about in our Air Arc Welding and Carbon Arc Gouging article.

GTAW (TIG): Precision Beads and Walking the Cup

TIG lays the most precise beads in welding. Freehand, with a pinky resting on the joint, gives full control of ripple spacing: each dab of filler rod sets one ripple, which is why clean TIG welds look so regular. On pipe and heavy grooves, welders walk the cup, rocking the ceramic nozzle side to side in a figure-eight to produce a consistent scale-like weave that is nearly impossible to match freehand. Aerospace and pressure-work standards lean on that consistency, as our Aerospace TIG Welding guide describes.

SAW (Submerged Arc): Wide, Smooth, Shallow Beads

Submerged arc welding hides the arc under a blanket of granular flux and lays wide, smooth, shallow beads with very low spatter and very high deposition rates. Weaving is common here, within code limits, and automated heads often oscillate in a simple zigzag to cover wide joints in a single pass. The trade-off is position: SAW beads only really work flat, and the slow, controlled travel speed produces excellent profiles with AWS D1.1-compliant reinforcement when parameters are set right.

Process	Preferred Bead	Typical Pattern
SMAW	Stringer (root: keyhole)	Straight drag, occasional crescent weave
GMAW short-circuit	Narrow stringer	Slight triangle or straight motion
GMAW spray	Wide stringer	Minimal weave, fast travel
FCAW	Stringer, drag technique	Narrow side-step only
GTAW	Freehand or walked weave	Figure-eight (walking the cup)
SAW	Wide oscillated bead	Zigzag, automated

Match the bead to the process, and the process will do half the work for you.

Beads in Every Position: Flat, Horizontal, Vertical and Overhead

Position is the biggest variable a welder controls besides the arc itself. Gravity never changes, so an overhead bead has little in common with a flat one. Joint geometry, travel angle, current and even the bead type you choose all shift as soon as the work rotates. Codes recognize this: positions are labeled 1G/1F through 4G/4F, and a procedure qualified flat may not be usable overhead without requalification. Understand what each position demands and you pick the right bead before you strike an arc, not after the metal starts sagging.

Flat Position: Where You Can Go Wide

Flat (1G groove, 1F fillet) is the forgiving position. Gravity pulls the puddle into the joint rather than away from it, so this is where you run the widest beads and highest deposition rates. Weaving is most acceptable here: a crescent or figure-eight across a wide groove spreads heat evenly and fills fast. Travel angles stay modest, roughly 5 to 15 degrees push or drag, and amperage can sit at the top of the recommended range.

Production work lives here. Because the puddle is stable, an all position welding rod run flat often performs like a dedicated flat-classified consumable, with deeper penetration and faster fill than the same rod manages anywhere else.

Horizontal: Fighting the Sag

In horizontal (2F, 2G) gravity works sideways. On a fillet the metal sags off the ceiling of the joint; on a groove it piles on the bottom edge and leaves the top unfused. The fix is a narrow bead: short stringers or a very tight side-to-side weave, no wider than about one to one-and-a-half electrode diameters, placed slightly above center so the puddle flows down into place.

Drop current a little from flat settings and keep the arc short; a long arc adds fluidity, and fluid metal runs downhill. In a multi-pass horizontal groove, stringers stacked bottom-up beat one wide weave every time, because each small bead freezes before the next goes on.

Vertical-Up: Slower, Stronger, Preferred

Vertical is a choice between two directions. Vertical-down is fast and looks clean, but it races ahead of the puddle and tends toward shallow penetration with an unconsolidated root. Vertical-up is slower and is the standard for heavy structural steel: deeper penetration and a narrower heat-affected zone give better mechanical properties. Bridge and heavy-plate specifications favor it, consistent with Federal Highway Administration guidance on steel bridge fabrication and the qualification rules in AWS D1.1.

The technique that makes it work is the shelf. Each bead sits on previously frozen metal, so the pattern matters: a triangle or J-weave deposits material low and pauses at the sides to fuse the toes, building a ledge that carries the next pass. Current drops 10 to 15 percent below flat settings and the arc stays tight. Weave width is limited in wide faces, so once the exposed weld face reaches about 1 inch (25 mm), the cap is split into layers of narrower stringers.

Overhead: Small, Fast, Controlled

Overhead (3G, 4F, 4G) is where puddle size decides success. A large pool overhead sags, drips and freezes as overlap or cold lap on the bead edges. The answer is small, fast stringers with reduced current and a short arc. Faster freeze keeps the metal where you put it, and lower heat input keeps the pool shallow enough for surface tension to hold it against the plate.

Weaving is possible overhead but demands tight control of side pauses; most welders prefer several small stringers because they are simply more reliable. Any hesitation leaves a lump, any long arc invites a drip. Fill the crater at termination, clean between passes, and watch the toes, since undercut and cold lap show up first here. Position-related defects are covered further in guides on common welding defects.

Practical Adjustments at a Glance

Position	Bead type	Current vs. flat	Travel angle
Flat (1G/1F)	Wide weaves or stringers	Full range	5–15° push or drag
Horizontal (2G/2F)	Narrow stringers, tight side-weave	Slightly reduced	5–10°, slight uphill bias
Vertical-up (3G/3F)	Triangle or J-weave on a shelf	Reduce 10–15%	5–10°, pointing slightly upward
Overhead (4G/4F)	Small, fast stringers	Noticeably reduced	5–15°, short arc throughout

Read the bead after every pass. A flat bead that sags means too much heat or too slow a travel; an overhead bead with rounded toes means the puddle got too large. Position work is also where fume and posture problems accumulate, so ventilation and protective equipment remain non-negotiable, per OSHA’s welding, cutting and brazing guidance. Master the four positions with stringers first, and the weaves that follow will be far easier to control.

Bead Defects: Identification, Causes and How to Fix Them

Even a well-chosen bead type can go wrong. The difference between a bead that gets ground out and one that passes inspection usually comes down to a handful of repeatable defects, each with a recognizable look on the bead surface and a predictable root cause. Learning to read your own welds this way is the fastest path to improvement: identify the flaw, trace it to the technique error, and fix the error on the next pass.

Discontinuity vs. Defect: Why Not Every Flaw Fails

Before the troubleshooting list, one important idea. In quality standards such as ISO 5817 and ISO 10042, a discontinuity is simply any interruption in the normal weld structure. It becomes a defect only when it exceeds the acceptance criteria for that application. A tiny slag trail that a visual inspector tolerates on a low-stress bracket may be a rejection on a pressure vessel or a bridge. That is why weld profile acceptance criteria are spelled out in codes like AWS D1.1, and why you should always know which standard your work is judged against before you strike an arc.

The Common Bead Defects and How to Fix Them

Here is the practical troubleshooting list every welder should be able to recite from memory.

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Defect	What it looks like	Typical cause	Corrective action
Undercut	A groove melted into the base metal along the weld toe	Excessive current, wrong travel angle, pausing too briefly at the weave edges	Lower amps slightly, slow the sides of the weave, reduce travel speed
Overlap (cold lap)	Weld metal spills over the toe without fusing	Too low current, too slow travel, arc length too long, dirty surface	Raise heat slightly, steepen the push angle, clean the joint
Porosity	Gas pockets or pinholes in the bead face	Contaminants, inadequate shielding gas, long arc	Clean and degrease, check gas flow, shorten arc length
Slag inclusion	Trapped slag visible on the face or found by NDT	Poor interpass cleaning or a convex underlying layer	Chip and wire-brush every pass, run flatter fill beads
Crater crack	A star-shaped crack at the bead termination	Breaking the arc abruptly on an unfilled crater	Hold the arc over the crater, reduce current as you fill it
Lack of fusion/penetration	Seam between weld and base metal, or an un-fused root	Cold joint, insufficient heat, poor joint prep	Increase heat, fix work angle, ensure proper root gap and land
Underfill	Weld sits below the parent metal surface	Too little filler, too-fast travel	Add a fill pass; slow down and add more filler
Excessive reinforcement	Weld is too tall or peaked	Too much filler or too slow a weave center	Add weave oscillation, increase travel speed, re-profile if needed
Burn-through	Hole melted completely through the joint	Too much heat on thin material	Reduce current, stitch the arc, increase travel speed
Spatter	Metal droplets scattered near the bead	Long arc, wrong polarity, wet or dirty base metal	Tighten arc length, verify machine settings, dry-clean the joint
Distortion	Workpiece pulls out of alignment	Excessive heat input and unbalanced bead placement	Tack well, alternate sides, favor stringers over wide weaves

The Three Technique Habits That Prevent Most of the List

Notice how many rows above trace back to just three habits.

• Crater filling. Crater cracks are one of the most common termination failures, and one of the easiest to prevent. When you break the arc abruptly, the shrinking, shrinking molten pool solidifies under tension. AWS guidance recommends holding the arc over the crater as you fill it slightly convex before breaking the arc. On a low-amperage machine, back the current down as you finish.
• Arc-length control. A long arc is behind undercut, porosity, spatter and poor shielding all at once. Keep it tight and let the electrode or wire do the work.
• Cleaning between passes. Slag inclusions almost never come from bad luck. They come from a skipped wire-brush, or from a convex underlying layer that the next bead couldn’t wet into. Chip it, brush it, look at it, then weld.

Finally, make inspection part of your routine, not the inspector’s job. Visual inspection, a bead profile gauge, and knowledge of OSHA welding hazard guidance for safe grinding and rework keep both your welds and your crew compliant. Catching a defect while the plate is still warm means it costs you a minute, not a rejection notice.

How to Practice and Perfect Every Bead Type (Plus Safety Essentials)

Reading about stringers and weaves will never put a good bead on plate. Bead control is a hand skill built through deliberate, repetitive drilling with honest feedback after every pass. The good news: you do not need a shipyard. A piece of mild steel plate, a few electrodes or a spool of wire, and a clear plan will take you from erratic ripples to consistent beads in every position.

Bead-on-Plate: The Drill That Builds Everything

Bead-on-plate is the standard drill in welding schools because it strips the joint out of the equation. Lay a plate flat, strike an arc, and run a straight bead while holding three variables steady: arc length (about the diameter of the electrode core for stick), travel speed, and work angle. Then do it again, changing one thing each time.

• Line drill: draw straight lines and run stringers on them. If the bead wanders, your hand speed or body position is drifting.
• Spacing drill: run parallel beads that tie into the previous one at a fixed overlap of roughly one-third to one-half bead width.
• Termination drill: fill every crater. Crater cracks almost always start at a bead that stopped dead instead of backing up and fading out.
• Cross-section drill: cut a bead, file and etch the face, and compare penetration depth to bead width. Nothing teaches heat control faster.

The 1-2-3 Rule for Consistent Ripples

Ripple spacing is rhythm. Count one as you pause at the left toe, two as you cross the center quickly, and three as you pause at the right toe. Even counts, even ripples. On a stringer, the same idea becomes a steady count so travel speed never races or stalls mid-bead.

Progress From Stringers to Weaves to Positions

Do not practice everything at once. Give each stage a week or two of plate time:

1. Flat stringers: consistent beads until the ripples look identical start to finish.
2. Narrow weaves: a tight zigzag no wider than about 1.5 times the electrode diameter, keeping the pause-at-the-sides discipline.
3. Actual joints: fillet and groove welds flat, where gravity is on your side.
4. Out of position: horizontal, then vertical-up, then overhead, each with its own rod choice and current. An all position welding rod guide helps you pick consumables rated for the position you are drilling.

For structured feedback, a formal aluminium welding course-style program, in aluminium or steel, puts an instructor on your travel angle before bad habits set.

Simulators, Video and the Weld Gauge

Augmented-reality trainers let students drill stringer and weave beads with zero consumable cost and instant repeatability, ideal for hand position before you burn real metal. Beyond that, film your passes with a phone on a tripod. Playback shows what your helmet cannot: shoulder tension, jerky repositioning, and arc length drifting near the plate edge.

Then measure instead of guessing. A simple weld gauge checks bead width, reinforcement height, and undercut depth against the profile acceptance criteria in AWS D1.1. A bead that looks fine under a helmet but reads high on the gauge is a bead that gets ground out.

Safety Essentials: Fumes, Arc Radiation and Hot Metal

Practice habits and safety habits start on day one. OSHA’s welding, cutting and brazing standard (29 CFR 1910.252) requires ventilation, fume control, and fire protection during arc welding, because the arc is only part of the hazard. Welding fume exposure, including manganese and hexavalent chromium from stainless steel, is a documented health hazard tracked by NIOSH, so engineering controls come before faith in a mask.

• Ventilation: local exhaust at the arc, or at minimum cross-ventilation pushing fumes away from your breathing zone. Never weld sealed without extraction.
• PPE: auto-darkening helmet with the correct shade, flame-resistant jacket and sleeves, gauntlet gloves, safety boots, hearing protection around grinders.
• Respiratory protection: a half-mask respirator with the right cartridge, used under a written program where limits may be exceeded.
• Fire and heat: clear combustibles, keep an extinguisher nearby, and treat every plate as hot long after the glow fades. Chalk and quench, never bare hands.

Which Bead Belongs Where: The Final Cheat Sheet

Situation	Bead to run
Root pass, thin material, overhead	Small, fast stringer
Horizontal fillet	Stringer or very narrow side-weave
Vertical-up groove or fillet	Stringer, or triangle/J weave to build a shelf
Wide cover or capping pass	Narrow weave, or split into layered stringers
Flat multipass fill	Stringers preferred; weave only to tie in the edges

Master the stringer first, because every other bead is a controlled variation of it. Add weaving only where the joint geometry demands width, keep the pauses at the toes, and let the gauge, not your pride, decide when a bead is finished. Beads do not lie, and once you can read your own, you already know which one belongs in the joint in front of you.

Frequently Asked Questions

What are the two main types of welding beads?

Stringer and weave. A stringer bead is laid in a straight line with little or no side-to-side motion, giving low heat input and good penetration. A weave bead uses an oscillating motion to cover a wider area per pass, which is useful for filling wide joints and cover passes.

Is a stringer bead stronger than a weave bead?

Not automatically. Stringers usually produce lower heat input and a finer-grained, tougher weld and HAZ, which is why codes favor them. But a weave bead welded at a properly qualified heat input can be just as sound — the WPS, not habit, determines what is acceptable.

When should you use a weave bead instead of a stringer?

Use a weave when the joint face is too wide to cover efficiently with stringers, when a cover pass needs a smooth wide profile, or in vertical-up fillet and groove work where a triangle or J-weave builds a shelf to support the puddle. Never weave an open root — it risks burn-through and lack of penetration.

What is a root bead and why is it so important?

The root bead is the first pass in a groove or pipe weld, tying the two members together at the joint root. Most weld cracks initiate in the root layer, and any lack of fusion or penetration there cannot be corrected by later passes — it must be ground out and repaired.

Why is my weld bead lumpy and uneven?

Uneven beads usually come from inconsistent travel speed, arc length that wanders, or an unstable work position. Stabilize your body, maintain a constant arc length, and practice steady travel on plate until ripple spacing becomes uniform before returning to the joint.

What causes crater cracks at the end of a bead?

Breaking the arc abruptly leaves a depression that solidifies from the outside in, creating tensile stresses and star-shaped cracks. Back up slightly or use a crater-fill setting to leave the crater slightly convex before extinguishing the arc.

How wide can a single weld bead be?

It depends on the code and procedure. AWS D1.1’s Table 5.1 requires a split-layer technique when the exposed weld face for the next layer is 1.0 inch (25 mm) or wider, and many WPSs limit weave width to a multiple of the electrode or wire diameter.

What does a good weld bead look like?

Uniform ripple spacing, consistent width, smooth tie-in at both toes with no undercut, minimal spatter, and slight convex reinforcement — no high crown, no overlap, no porosity or crater cracks. Appearance is a strong first indicator, though soundness still requires NDT where specified.