Carbon fiber sheet is one of the easiest carbon products to order well, because a good CAD file plus a few decisions gets you a finished part. This guide covers those decisions so your CNC-cut carbon plate arrives right the first time.

Solid vs cored panels

The first choice is construction:

  • Solid laminate — plies of carbon cured into a dense plate. Strong and thin; best for brackets, plates, gussets and small structural parts.
  • Cored sandwich — thin carbon skins bonded to a foam or aluminum-honeycomb core. Like an I-beam in panel form: very high bending stiffness at very low weight. Best for large decks, tables, robot chassis and drone plates.

Thickness and sheet size

Solid plate is commonly 0.5–20 mm thick; cored panels can be much thicker. Sheet sizes run up to roughly 1000 × 2000 mm. Thicker equals stiffer but heavier, so for large flat parts a cored panel usually beats a thick solid plate on weight. If you are replacing an aluminum plate, send its thickness and we match stiffness at lower weight — see carbon vs aluminum.

CAD files and what to send

  • Flat profiles (outline, holes, slots): a DXF or DWG is ideal.
  • 3D features (pockets, chamfers, counterbores): send a STEP file.
  • Always include critical dimensions, hole positions and tolerances, plus which face is cosmetic.
  • Only have a sample? We reverse-engineer it into a drawing.

Tolerances and edge quality

CNC routing typically holds about ±0.1 mm on profile and holes, tightening to ±0.05 mm on critical features. Carbon is abrasive and can chip if cut with the wrong tooling and feeds, so a good shop uses diamond-coated or PCD tooling and correct speeds for clean edges. Mark which dimensions are critical so we fixture and inspect for those.

Edge sealing and finishing

Cut edges expose the laminate, so decide how they are treated: resin or paint sealing to stop fraying and moisture ingress, chamfers or radiused corners for handling and looks, and surface gloss or matte finish. For visible parts specify a cosmetic face and sealed edges; for hidden structural parts you can skip cosmetic finishing to save cost. Ready to quote? Send your DXF or STEP file and we confirm feasibility, tolerance and price.