Part spacing: separate kerf, remaining material and sheet margin

Set spacing from a tested cutting process and the material that must remain between cuts. A single universal distance cannot account for every tool, thickness, fixture and cutting strategy.

Keep the three settings distinct

Kerf is the width removed by the cut. Minimum spacing is the additional material you want between neighbouring cuts. Sheet margin is a separate allowance at the sheet boundary. In NestForge, the required distance between part contours is kerf + minimum spacing. The sheet-edge inset is margin + kerf / 2. Do not apply the inter-part formula to the sheet edge.

Work through a numerical example

With a measured kerf of 0.2 mm, minimum spacing of 1.0 mm and margin of 3.0 mm, the required contour-to-contour gap is 1.2 mm and the sheet-edge inset is 3.1 mm. These are arithmetic examples, not recommended laser settings. For a router, also check cutter diameter and access. For plasma, allow room for lead-ins and a skeleton that remains stable. Thin sheet can move even when the drawing has enough geometric clearance.

Verify the exported cutting job

Keep the source dimensions unchanged and set kerf compensation in the appropriate CAM operation. Review inside and outside cuts, lead-ins, tabs, clamps and the sequence. NestForge does not create these toolpaths. If the CAM preview uses space outside a part contour, increase the layout allowance or change that operation before cutting. Save the material, thickness and machine settings with your tested values so the spacing is repeatable.