Design for Laser Cutting — DFM Guide

Minimum Feature Size

Minimum hole diameter: 1x material thickness (1.5x preferred). Minimum slot width: 1x material thickness. Minimum web between features: 1.5x material thickness. Below these limits, the beam dwells too long and creates excessive heat, melt-through, or distortion. A 0.125" hole in 0.125" steel is technically possible but won't be round.

Tab & Slot Joinery

Design self-locating joints directly into your laser-cut parts. A tab on one part engages a slot on the mating part, creating a self-fixturing assembly that reduces welding time by 30–50%. Tab width: 2x material thickness minimum. Slot length: tab length + 0.010" clearance. This is free on laser (just geometry in the DXF) and saves enormous time downstream.

Bend Allowance Integration

If the part will be brake-formed after cutting, include bend relief notches in the laser pattern. Bend reliefs prevent edge cracking and ensure clean fold lines. Relief width: material thickness. Relief length: 1.5x material thickness past the bend line. Many fab shops expect designers to include bend reliefs in the flat pattern — don't make the shop add them.

DXF File Best Practices

Submit DXF files on a 1:1 scale in inches. All geometry on a single layer. No duplicate lines (laser will cut the same edge twice). No open polylines. No splines — convert to polyline arcs. Include bend lines on a separate layer if the part will be formed. Label material, thickness, and quantity in the filename or accompanying notes.

Nesting Awareness

Parts are nested on standard sheet sizes (48"×96", 48"×120", 60"×120"). Rectangular parts nest most efficiently. Parts with complex outlines waste more material. Common-line cutting (adjacent parts share a cut edge) saves time and material — design parallel straight edges where possible. If ordering large quantities, ask about nesting optimization.

Sharp Corners & Radii

Laser can produce sharp outside corners (the beam simply turns). Inside corners: the beam will produce a radius equal to approximately half the kerf (0.003"–0.006"). If truly sharp inside corners are required, specify laser + milling. For bend relief, use a small radius (R = material thickness) rather than a sharp notch to prevent stress cracking at the bend.