Laser-Cut Plastic Parts: Acrylic, Delrin, UHMW and G10

Which plastics laser cut cleanly, and which are routed or waterjet cut

Acrylic and Delrin are the two plastics quoted laser cut; the rest are quoted routed or waterjet cut. UHMW, HDPE and polycarbonate are quoted as CNC routed, and G-10/FR-4 as waterjet cut. Name the material and thickness on the print. A print for one of the routed or waterjet materials is still quoted here as a cut plastic part, with the process named on the quote.

The split follows what each plastic does under a beam. Wikipedia’s PMMA page states that acrylic "vaporizes to gaseous compounds (including its monomers) upon laser cutting, so a very clean cut is made" (source 1), and its POM page states that "POM sheets can be cut cleanly and accurately using an infrared laser" (source 2); Delrin is a trade name for acetal homopolymer (source 2). The Minneapolis College of Art and Design’s laser lab lists HDPE as melting and able to catch fire, polycarbonate as not cutting well and discoloring, and fiberglass and epoxy resins as giving off fumes (source 6), and a hackerspace’s laser guide says the same of HDPE and polycarbonate (source 7). UHMW is a polyethylene (source 5), so it is quoted the same way as HDPE, and G-10/FR-4 is glass cloth in epoxy (source 3), so it is not quoted laser cut. A material that does not laser cut cleanly is quoted routed or waterjet cut instead, and the quote says which.

Acrylic: the cut edge and what goes on the print

Acrylic is the plastic a laser cuts most cleanly: Wikipedia’s PMMA page says it vaporizes to gaseous compounds under the laser, so a very clean cut is made (source 1). It is quoted in clear and in colors. Clear acrylic transmits up to 92% of visible light at 3 mm thickness and has impact strength higher than glass (source 1), which is why guards and windows are drawn in it.

Where the print gives no tolerance, the quote states the tolerance used. A print for an acrylic panel puts its critical dimensions on hole positions and overall size, not on the edge profile, and calls out cast or extruded acrylic where it matters: Wikipedia says cast acrylic has higher resistance to crazing when exposed to solvents than extruded acrylic. Wikipedia adds that pulsed laser cutting leaves internal stress at the edge, and solvents, even ammonia-based glass cleaner, can turn it into crazing (source 1), so a print for a part that will be cleaned or see solvents says so. Metal sheet parts are on the laser-cut aluminum page. Where a plastic faceplate needs a machined counterbore or a threaded insert, panels and faceplates covers how the second operation is added to the same order.

Delrin, UHMW and HDPE: wear parts

Wikipedia’s POM page says POM has very little shrinkage, 0.17% from 165 °C to 20 °C (source 2), which suits a flat Delrin part that has to hold its size, such as a wear strip, a slide pad, a bearing plate or a spacer.

UHMW is a polyethylene with a very low coefficient of friction, lower than acetal’s, and it is highly resistant to abrasion (source 5). UHMW and HDPE are quoted CNC routed, not laser cut, and a print for a UHMW wear strip or an HDPE guard names the edge condition it wants. If a plastic part needs threads, a bore with a fit, or a pocket, it moves to the machined side: machined Delrin and acetal covers turned and milled acetal, and secondary machining on cut blanks covers adding a machined feature to a flat plastic blank as one order.

G10/FR4 for insulators and fixture plates

G10 is glass cloth in epoxy, and it is quoted waterjet cut, not laser cut. Wikipedia’s G-10 page (en.wikipedia.org/wiki/G-10_(material)) describes it as layers of glass cloth soaked in epoxy resin and compressed under heat until cured, originally a printed circuit board substrate (source 3), and its FR-4 page describes FR-4 as the flame-resistant version that has replaced G-10 in most applications, with a listed dielectric strength of 20 MV/m (source 4). Wikipedia’s G-10 page lists a high level of electrical insulation among its properties (source 3), which is why G10 is drawn for insulator plates, standoff bars, battery spacers and test-fixture plates.

A G10 test-fixture plate is a typical example: a flat plate with a pattern of probe holes and mounting holes that carries a board or a device under test. Hole positions are the tolerance that matters, so the print gives them their own; a hole that must locate a pin or a bushing is drawn to be reamed or drilled after cutting and quoted that way. Custom fixtures built to print covers the fixture side, and plates and spacers covers flat plates in every material. For a plastic that must run hot or resist chemicals, PEEK is the machined grade: Wikipedia lists it as highly resistant to thermal degradation and readily machinable by CNC (source 8), so it is quoted from rod or plate rather than cut from sheet. The fixture side of G10, matched plates and dowel pairs, is on G10 and phenolic fixtures.

Finishes, print items and how plastic parts are inspected

Cut plastic parts are quoted as cut, with no finish unless the print names one. A finish called out on the print is quoted with the part, and a print that wants a specific edge says so. The laser-cut parts hub lists the finishes that apply on the metal side, and laser vs waterjet vs CNC explains when a plastic part is better machined from plate than cut from sheet.

A complete print for a cut plastic part names the polymer and grade (cast or extruded acrylic, Delrin, UHMW, HDPE, G-10 or FR-4), the thickness, color where it matters, the tolerance block, edge condition and quantity. Send a DXF or STEP plus a PDF print, or any file you have. A dimensioned sketch, a new sample part or photos are enough to start; the CAD work is then quoted as its own line, and the quote lists anything missing. A fully dimensioned 2D PDF is quoted without a CAD line. Every part inspected against your print before it ships. Quantities run from one plate to production runs of 10,000; there is no minimum, and one plate is a normal job.

Sources

All accessed 4 October 2026. Where a figure here differs from your print, the print governs.

1. Wikipedia, "Poly(methyl methacrylate)": en.wikipedia.org/wiki/Poly(methyl_methacrylate) (vaporizes to gaseous compounds upon laser cutting; pulsed laser cutting introduces internal stresses that produce stress crazing at the cut edge on exposure to solvents, even ammonia-based glass cleaner; less prone to combustion and discoloration during laser cutting than polycarbonate; transmits up to 92% of visible light at 3 mm; impact strength higher than glass; cast acrylic has higher resistance to crazing when exposed to solvents).

2. Wikipedia, "Polyoxymethylene": en.wikipedia.org/wiki/Polyoxymethylene (cut cleanly with an infrared laser; shrinkage 0.17% from 165 °C to 20 °C; Delrin named as a POM homopolymer).

3. Wikipedia, "G-10 (material)": en.wikipedia.org/wiki/G-10_(material) (glass cloth soaked in epoxy resin and compressed under heat; high level of electrical insulation; circuit board substrate; epoxy resin is flammable and burns vigorously, giving off poisonous gases; FR-4, with flame retardant additives, has replaced G-10 in certain applications).

4. Wikipedia, "FR-4": en.wikipedia.org/wiki/FR-4 (woven fiberglass cloth with an epoxy resin binder, flame resistant; has replaced G-10 in most applications; dielectric strength 20 MV/m).

5. Wikipedia, "Ultra-high-molecular-weight polyethylene": en.wikipedia.org/wiki/Ultra-high-molecular-weight_polyethylene (a subset of thermoplastic polyethylene; very low coefficient of friction, significantly lower than nylon and acetal; highly resistant to abrasion).

6. Minneapolis College of Art and Design, Digital Lab, "Materials Not Safe to Laser Cut": intranet.mcad.edu (a college lab handout: HDPE melts and can catch fire; polycarbonate does not cut well and discolors; fiberglass emits fumes and does not cut well; epoxy or phenolic resins emit toxic fumes; PVC results in chlorine gas; ABS results in cyanide gas). Undated.

7. Root Access Hackerspace, "Laser Cutting", older revision of 29 December 2023: rootaccess.org/wiki/Laser_Cutting/rev9 (a member-edited hackerspace wiki: polycarbonate cuts very poorly, discolors and catches fire; HDPE melts and catches fire; PVC emits chlorine gas; ABS emits cyanide).

8. Wikipedia, "Polyether ether ketone": en.wikipedia.org/wiki/Polyether_ether_ketone (highly resistant to thermal degradation and to attack by organic and aqueous environments; readily machinable by CNC in its solid state).