Ask a seam welding line what went wrong when seams drift out of tolerance, and the answer is rarely the alloy — it is the profile. The wheel face decides where current concentrates, how the strip enters the weld, and how the seam tracks through the wear cycle. This guide walks through the four profiles we cut most often, and the selection logic that connects each one to the seam you are trying to produce.
Why profile outranks alloy
Two wheels of identical material can behave completely differently on the same strip depending on face geometry. The profile sets current density at the contact, the mechanical entry angle of the sheet, and the contact width that the wheel wears back to. Profile selection, more than anything else on the wheel, drives seam consistency — which is why it should be chosen from the weld requirement outward, not from a catalogue inward.
Flat face
The general-purpose choice. A flat face distributes current over a wider contact, which suits roller-spot work and general seam applications where seam width tolerance is generous. Flat faces are also the most forgiving to dress: restoring them is a simple truing cut, and the profile is held almost by accident through the wear cycle.
Choose flat when: seam width tolerance is wide, the weld is intermittent (roller-spot), or you are standardizing spares across mixed stations.
Single and double bevel
Bevels concentrate current on the sheet side of the lap, which makes them the standard choice for can-body seams, drum lids, and other overlapping joints where the nugget must punch through both sheets reliably. A single bevel biases penetration to one side; a double bevel symmetrizes it for seams where both sides must finish clean — food cans, for example, where the inside bead matters.
The trade: bevel edges are the first geometry to round over under wear. High-force schedules will want the harder W/Cu 75/25 grade to hold the bevel longer; maintenance shops that dress on a fixed interval often run W/Cu 70/30 (≈ 42% IACS) and accept the faster dress rate as the price of headroom in current.
R profile
An R profile meets the strip with a radius instead of an edge, which changes the entry angle progressively across the contact. That matters in two places: curved seams, where a sharp edge would dig on the inside of the curve, and thin or delicate strip, where edge contact tends to mark or indent the surface. R faces are also common on tube-mill work where the seam approaches the wheel at an angle.
Knurled face
Knurling is a drive feature as much as a welding one. A knurled face grips and drives the strip, and its grooves continuously clean the contact track — useful on tube mills, where the strip must not slip against the wheel and debris in the track would otherwise build up. Knurl geometry is cut to drawing and should be treated as a wear item: the knurl form, like any edge, wears, and an effective knurl is a sharp one.
Match the profile to the drive method
One selection input buyers often miss is how the wheel is driven:
- Gear-driven wheels put torsional load through the bore and keyway — the face profile is free to be chosen purely for the weld. We cut the keyway and the profile to match your shaft drawing.
- Friction or knurl-driven wheels put the drive load through the face itself. Here the profile and the knurl are one design decision, and the face needs enough contact geometry to transmit drive without slipping at line speed.
Tell us the drive method when you order — it changes what we check before the wheel ships.
How profiles wear, and what to do about it
All four profiles wear, but they do not wear the same way: flat faces wear widest, bevel edges round over, R profiles grow their radius, knurls dull. What matters for the line is that the wear is slow and even, so that dress intervals and reorder timing are predictable. That predictability — more than raw life — is the argument for infiltrated tungsten copper: the face dresses rather than mushrooms, so the profile you specified is the profile you keep retouching, not one you keep chasing.
Get a quote
Send us the seam requirement — strip gauge, coating, weld speed, drive method — and we will recommend a profile and cut wheels to your drawing with bore H7 and 0.02 mm runout. Request a quote; standard lead time is 10–14 days with no minimum order.