A metal stud, a ceramic ferrule, and a fraction-of-a-second arc — the stud becomes a weld that needs no holes, no bolts, and no access behind the plate.
Stud welding fuses a metal stud directly to a base plate with an arc. The gun lifts the stud a set distance, an arc melts its tip and a pool in the plate, and at the end of the timed cycle the stud plunges into the pool. A full weld, under a second.
A ceramic ferrule surrounds the stud base during the weld — it concentrates the arc, contains the molten metal, and shapes the fillet. It cracks off after each weld and is replaced per stud. The result is a fastener that is also a weld: no holes, no threads engaged, no access from behind.
Mild steel drawn-arc studs on plate — typical hand-gun settings.
| Stud dia | Current | Arc time | Lift | Ferrule |
|---|---|---|---|---|
| 1/4 in | 500–700 A | 0.2 s | 1/16 in | #4 |
| 3/8 in | 800–1000 A | 0.25 s | 1/16 in | #6 |
| 1/2 in | 1200–1500 A | 0.3 s | 3/32 in | #8 |
| 5/8 in | 1500–1800 A | 0.35 s | 3/32 in | #10 |
| 3/4 in | 1800–2200 A | 0.4 s | 1/8 in | #12 |
| Property | Drawn Arc | CD Stud |
|---|---|---|
| Base metal | Plate, heavy sections | Thin sheet |
| Weld time | 0.2–1 s | 1–10 ms |
| Stud sizes | Up to 1 in | Up to 3/8 in |
| Ferrule | Yes, per weld | Not required |
| Burn-through risk | High on thin gauge | Negligible |
| Typical jobs | Shear studs, pipe pins | Nameplates, trim, wiring |
DC stud welding rectifier — delivers the timed, high-current pulse.
Browse power sources →Hand, fixed, or magazine guns — the lift and plunge are built into the gun.
Browse automation →Studs matched to base metal, ceramic ferrules sized to the stud.
Browse consumables →Sets current and arc time per stud — the schedule lives here.
Clean, tight ground path — a poor ground makes weak welds.
Grinder, wire brush, and slag hammer for the fillet around each stud.
Hammer and bending tool — the daily check that welds are sound.
Stud welding runs in every position — but gravity decides the pool, and the equipment follows.
The natural position — best pool control, highest quality, fastest production.
Wall studs and shear connectors — the ferrule keeps the pool in place.
Deck and soffit studs with special guns — the pool holds in the ferrule cup.
Magazine and robot guns on plate lines — thousands of studs per shift.
One process, three arc styles — the application picks the technique.
The standard — timed arc, ferrule-contained pool, studs to 1 in on plate.
Millisecond pulse for thin sheet — no ferrule, no burn-through, small studs.
A shorter, gentler arc for thinner base metals with drawn-arc equipment.
Argon replaces the ferrule — used where ferrule marks or debris are a problem.
Magazine-loaded guns feed studs automatically — production rate without the reload.
Hammer-bend a stud from every batch — a stud that bends and doesn't break passes.
Stud welds fail in a second — the defects are visible in the fillet within seconds too.
Appearance
A thin, raised collar — the pool never really bit the plate.
Causes
Current too low or arc time too short for the stud.
Prevention
Set the schedule from the stud chart and verify with a bend test.
Appearance
Pitted, spongy fillet — gas trapped in the fast-freezing weld.
Causes
Dirty plate or stud, or a damp ferrule.
Prevention
Clean both parts; store ferrules dry.
Appearance
A groove where the fillet meets the plate — a stress notch.
Causes
Arc too hot or the pool pulled away from the base.
Prevention
Lower current, check ferrule fit, keep the gun square.
Appearance
The stud leans — the fillet is fat on one side, starved on the other.
Causes
Gun not square to the plate or a worn chuck.
Prevention
Square the gun, replace the chuck, check the locator feet.
Appearance
A cold joint — the stud sits on the plate without fusing.
Causes
Lift too small, low current, or a contaminated stud end.
Prevention
Check lift and current; use fresh, clean studs.
Appearance
Metal beads around the weld — the pool threw material.
Causes
Current too high or the ferrule damaged.
Prevention
Dial the schedule down; fit a fresh ferrule.
Appearance
A hole or sag behind the weld on thin plate.
Causes
Drawn-arc heat on thin gauge metal.
Prevention
Switch to CD welding or a short-arc schedule.
Appearance
The stud snaps clean at the fillet — a hammer test catches it.
Causes
Wrong stud chemistry for the plate or cold weld.
Prevention
Match material grades; verify schedule with bend tests.
The documents behind stud weld quality, material, and qualification.
| Standard | Covers |
|---|---|
| AWS D1.1 | Structural steel — shear studs and their testing |
| AWS D1.5 | Bridge welding — deck stud rules |
| AWS C5.4 | Recommended practices for stud welding |
| ISO 14555 | Arc stud welding of metallic materials |
| ISO 13918 | Studs and ceramic ferrules for arc stud welding |
| ASME Section IX | Stud weld qualification for pressure equipment |
| ASTM A108 | Stud material — steel bars for studs |
| EN ISO 14555 | European adoption of the stud welding rules |
All-in-one machine settings helper for a fast stud schedule starting point.
Current × arc time — the number that controls penetration per stud.
Set argon flow for gas-shielded stud work and CD welding.
Studs replace filler — this covers the welds and repairs around them.
Which process fits thin sheet vs plate — drawn arc or CD.
See lift, plunge, and hammer tests on real steel.
Watch the process sections — stud positioning, ferrule fitting, and bend testing — on real metal.
Watch VideosA shop-floor cheat sheet with the schedule table, ferrule sizes, and test criteria.
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