What tolerance can laser cutting hold?

A fibre laser cutting carbon or stainless steel typically holds +/-0.1 mm to +/-0.15 mm on feature position for sheet up to 3 mm, widening slightly on thicker or larger parts. The cut edge itself is square within a fraction of a millimetre. For holes smaller than the material thickness the tolerance is wider because the slug is hard to eject cleanly.

What tolerance can sheet metal bending hold?

Bend angle is held to about +/-1 degree and the bent dimension (leg length) to roughly +/-0.25 mm to +/-0.5 mm, depending on material and tooling. The flat length is calculated, not measured, so leg-length accuracy depends on the K-factor used and on springback, which is why stainless and high-strength steel need overbending.

How tight can a hole be punched or lasered?

As a rule, keep a hole diameter at or above the material thickness for clean ejection; below that, specify laser cutting and expect a wider tolerance. For threaded holes, use a rivet nut or tapped insert sized to the material rather than tapping thin sheet directly, which strips easily.

Should I use GD&T or plus/minus tolerances?

For enclosures, plus/minus on each dimension is usually enough and cheaper to inspect. Use GD&T (datums, position, flatness) when parts must mate across assemblies or locate on a reference surface. Over-specifying GD&T on a simple cover just adds inspection cost, so match the scheme to what actually matters for fit.

How do I specify tolerances without over-paying?

State a general tolerance block (for example +/-0.25 mm) and then only tighten the dimensions that affect fit or mating. Tightening every dimension forces slower setup, more inspection and higher scrap. We quote to the tolerance you state and flag any call-out that will be expensive to hold before cutting.

What about powder-coat thickness eating into tolerance?

A powder coat adds about 60-120 microns per face. If a bore or a slip-fit dimension is critical, call out the tolerance on the bare metal and note 'after finish', or mask the feature. We mask threads and precision bores on request so the coating does not close them up.

Sheet Metal Enclosure Tolerances: A Practical Guide

Laser cutting holds feature position to about 0.1 mm; bending holds angle to about 1 degree and leg length to 0.25-0.5 mm. The cheap way to specify is a general tolerance block plus tight call-outs only where parts must mate — and to remember that powder coat adds 60-120 microns per face.

Cut: +/-0.1 mm

Fibre laser holds feature position to about 0.1-0.15 mm on thin sheet. Edge squareness is a fraction of a millimetre.

Bend: +/-0.5 mm

Angle to about +/-1 degree, leg length to 0.25-0.5 mm. Springback in stainless needs overbending.

Finish eats it

Powder coat is 60-120 microns per face. Mask bores and threads or tolerance the bare metal.

Reference

Tolerances by process

These are the working ranges we quote to on enclosure work. They are starting points — the real number depends on material, size and which dimension affects fit.

Process	Typical tolerance	Note
Laser cut, position	+/-0.10 to 0.15 mm	Thin sheet; wider on plate
Laser cut, edge squareness	< 0.5 mm over 10 mm	Clean, dross-free with nitrogen
Bend angle	+/-1 degree	Overbend for stainless/HSLA
Bend leg length	+/-0.25 to 0.50 mm	From K-factor + springback
Hole diameter	>= material thickness	Below that, expect wider tol

Always state a general tolerance block and tighten only the dimensions that affect assembly. Over-tolerancing raises setup, inspection and scrap.

Specifying

Tighten only what matters

The most common quoting problem is a drawing where every dimension is +/-0.1 mm. That forces slow setup and 100% inspection for no fit benefit. Put a general block (+/-0.25 mm) on the drawing and tighten the five dimensions that actually mate. We flag the expensive call-outs at DFM review so you can relax them before the price is fixed.

Bend allowance calculator

Fit

Finish changes the number

Powder coat is 60-120 microns per face. A slip-fit bore or a thread that is not masked will close up after coating. Call tolerance on the bare metal and add 'after finish', or have us mask the feature. The same logic applies to zinc plating and anodizing, which also add thickness.

State tolerance on bare metal for bores
Mask threads and precision holes before coating
Add coating thickness to any slip fit
Confirm plating/anodize buildup with us

FAQ

Tolerance questions

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Send the drawing, we flag the costly tolerances

Upload a DXF, STEP or PDF. Our DFM review marks the dimensions that are expensive to hold and suggests a general block that keeps the fit and lowers the price.

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