How to Automate Fillet Welding on H-Beams & Box Beams | Automatic Fillet Welding Machine

Why Fillet First

An angle carriage follows the corner instead of the plate

What makes fillet welding slow is not the welding, it is the position: the welder follows a corner with the torch at 45°, at the same travel speed, for metres at a time. An angle carriage rolls along the workpiece with the torch locked at the correct angle and distance, so leg length stays constant and the bead looks the same at the end of the beam.

Torch angle and stick-out locked by the machine — 45° fillet held accurately over the whole run
Adjustable oscillation for leg length and throat thickness
Single-torch and double-torch versions — twin torches weld both sides of a beam in one pass
Intermittent welding function for stitch welds
Runs on flat, vertical or slightly inclined work; magnetic wheels hold on steel

What we recommend: JJ / GJ series angle welding carriage — single torch for access-limited joints, double torch when both legs of an H-beam can be welded at once.

See the JJ / GJ Fillet Carriage

Angle welding carriage welding a fillet weld on an H-beam

Automatic fillet welding on a fabricated steel beam

Selection Table

Fillet Joint to Machine

Fillet weld / workpiece	Recommended machine	Note
H-beam web-to-flange fillet (one side at a time)	JJ / GJ single-torch carriage	Travelling on the flange, torch at 45°
H-beam both sides in one pass	GJ double-torch carriage	Two torches, mirror-symmetrical setup
Box beam and column fillets	JJ / GJ carriage with guide wheels	Guide follows the corner consistently
Stitch / intermittent fillet welds	JJ carriage with intermittent function	Set weld length and gap length, then repeat
Small brackets and tight details	Manual	Machine access does not pay off below a certain size

Leg length consistency comes from two things: a locked torch angle and a constant travel speed. Both are what the carriage provides, which is why fillet welding is usually where shops see the clearest improvement.

Method

Setting Up a Fillet Weld on a Carriage

SET 01

Set the Angle

Torch at 45° to both legs, wire aimed into the root. The carriage bracket keeps it there for the full run.

SET 02

Set the Leg Length

Travel speed, wire feed and oscillation width together determine the leg: adjust once on a scrap beam, then repeat for the batch.

SET 03

Guide Along the Corner

The guide wheel or magnetic wheels follow the joint, so the torch does not wander as the beam bows or the corner varies slightly.

SET 04

Repeat for the Batch

Once the parameters are set, every identical beam in the lot gets the same weld — which is the real gain when you weld hundreds of the same detail.

FAQ

Questions We Get Asked Before the First Quote

Can one machine weld both sides of an H-beam?

Not in one pass with a single torch — the carriage welds the leg it is set up for, then you reposition. For both sides simultaneously, the GJ double-torch version is the answer: two torches on one carriage, one pass down the beam.

Does it work on vertical and overhead fillets?

Vertical and inclined fillets are normal work for the angle carriage, and magnetic wheels hold the machine on the workpiece. Overhead work is limited by the process and the operator, so it is worth discussing the specific joint before ordering.

What about gaps and fit-up variation?

The carriage holds the torch at a constant angle and distance, so a constant gap welds consistently. Where fit-up varies joint to joint, the operator adjusts travel speed at the remote, or you fixture the joint better — the machine cannot compensate for a gap that changes.

Is it worth it for short fillets?

Below roughly a metre of continuous fillet, the setup time can eat the gain. The break-even point is really the batch size: if the same detail repeats all day, a carriage pays off even on short runs.

Keep Reading

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How to Automate Fillet Welding on H-Beams, Box Beams and Frames