Sheet metal fabrication: laser, bend, weld, tap
Enclosures, chassis, brackets and frames up to 1000 × 600 × 95 mm, cut, formed and welded, then inspected and packed on the same route as machined parts.
What the process covers
Flat parts and blank outlines cut from sheet, with hole patterns and reliefs in the same program. Small holes below roughly the sheet thickness start to taper, so a pierced hole of 1 mm in 2 mm steel is a design question, not a cutting question.
Bend radius follows the material and the tooling: roughly 1× thickness for mild steel and aluminium, more for high-strength alloys. The K-factor used to flat-pattern the part decides whether the folded box closes on dimension.
MIG and TIG for steel and aluminium, with dressing on cosmetic faces. Weld distortion is managed through sequence and fixturing, then the part goes to powder coating or painting if appearance matters.
Tapped holes in thin sheet pull out under load. Where a thread has to take real torque, a rivet nut or a welded boss is the honest answer, and it is cheaper to design it in than to repair it later.
Tolerance versus machining
| Item | Sheet metal | CNC milling |
|---|---|---|
| General tolerance | ±0.1 mm | ±0.05 mm |
| Hole position | ±0.1 mm | ±0.02 mm |
| Flatness | Not controlled as standard | 0.02 mm achievable |
| Max size | 1000 × 600 × 95 mm | 1000 × 600 × 400 mm |
| Cost at 50 pcs | Lower for thin parts | Higher, more material removed |
| Cost at 5 pcs | Tooling and setup dominate | Competitive, no tooling |
| Design change | New program, cheap | New program, cheap |
Drawing details that decide the price
A bend that runs into a corner tears unless the corner is relieved. A 0.5 mm relief at the bend line costs nothing at design and removes a hand-finishing operation from the route.
A hole closer to the bend line than about 1.5× thickness plus the bend radius deforms during forming and will not take a fastener cleanly.
"Weld all round, dress flush" is a very different price from "weld as required for strength". Say which faces are visible, and the finishing cost stops being a guess.
5052 bends better than 6061 in the same thickness, and 304 work-hardens faster than 301. Naming the grade for formability, not just for corrosion, avoids a batch of cracked flanges.
Questions we get on this process
Yes, and it is the usual reason buyers consolidate here. A folded cover with a machined sealing face arrives as one assembly with one inspection report.
Up to about 6 mm for laser cutting and forming within the stated envelope. Above that, machining or a different process is usually cheaper and more accurate.
Yes, both, coordinated with the forming operation. Threaded holes and mating faces are masked so the coating does not change the fit.
It is not guaranteed by the process. If a panel needs flatness, the design should add a machined or formed stiffening feature, or the flatness requirement should be moved to a machined component.
Send the folded part and the machined face as one file.
We will tell you which features belong in sheet metal and which need machining after forming, and quote the assembly as one line.
From the shop notes
Longer answers to the questions these pages raise.