Acrylic scratches more easily than glass. When a part has to stay clear under wiping, handling or abrasion, there are three routes: a hard-coated (abrasion-resistant) grade, a design that protects the surface, or a different material. How to choose, and how to write the requirement so a supplier can test against it.
Name the test, the load and the pass mark — “scratch-resistant” alone cannot be checked
To get scratch-resistant acrylic, specify either a hard-coated (abrasion-resistant) PMMA grade or a design that keeps abrasion off the visible face, and write a measurable requirement rather than the word “scratch-resistant”. The usual measures are pencil hardness (ASTM D3363), haze increase after a Taber abrasion test (ASTM D1044), and a steel wool rub test with a stated grade, load and number of strokes. Hard coatings greatly improve wiping and cleaning resistance, but they limit fabrication: coated sheet generally cannot be bent tightly or thermoformed without cracking the coating, cut edges are uncoated, and the coating must suit any cleaner used on it. Standard cast and extruded acrylic have similar surface hardness, so switching between them does not solve a scratch problem.
Three routes to a surface that stays clear
| Route | What it is | Best for | Limits |
| Hard-coated acrylic | PMMA sheet with a cured abrasion-resistant coating on one or both faces | Flat windows, covers and screens that are wiped often | Little or no bending or forming; uncoated edges; coating-specific cleaners |
| Protective design | Recessed faces, raised edges, replaceable cover sheets, film left on until installation | Displays, guards and enclosures handled in use | Changes the drawing; needs agreement early |
| Different material | Glass, or a coated polycarbonate where impact also matters | Very high abrasion, frequent harsh cleaning | Weight, breakage, cost and fabrication change |
Tests you can write into a specification
| Test | What it measures | How to write it |
| Pencil hardness (ASTM D3363) | Hardest pencil grade that does not scratch the surface | Name the minimum pencil grade and the load |
| Taber abrasion (ASTM D1044) | Increase in haze after a set number of cycles with abrasive wheels | Name the wheel, load, cycles and maximum haze increase |
| Steel wool rub | Visible scratches after rubbing with steel wool | Name the steel wool grade, load, strokes and acceptance (e.g. no visible scratches at a stated viewing distance) |
| Cleaning resistance | Surface after repeated wiping with the actual cleaner | Name the cleaner, cloth and number of cycles |
The supplier’s data sheet should state the test method and conditions behind any hardness or abrasion figure. A number without its method cannot be compared with another supplier’s number. Our acrylic appearance standards explain how visible defects are judged on finished parts.
What a hard coating changes in fabrication
| Process | Effect on coated sheet |
| Bending and thermoforming | The coating can crack; design coated parts flat or confirm the minimum radius with the coating supplier |
| Cutting and machining | Edges and machined features are uncoated; chips at the cut can lift coating if tools are dull |
| Bonding | Solvent cement will not bond through the coating; joints are placed on uncoated edges or the coating is removed locally |
| Printing and graphics | Inks and adhesives may not key to the coating; print the uncoated face or test adhesion first |
| Protective film | Leave it on through fabrication and shipping; remove at installation |
Keeping uncoated acrylic clear in service
Many scratch problems are cleaning problems. Dry wiping drags grit across the surface; paper towels and ammonia glass cleaners make it worse. Wash with mild soap and water and a soft microfibre cloth, rinse, and dry by blotting. Light scratches on uncoated acrylic can be polished out; deep ones need sanding and polishing. Our guide to removing scratches from acrylic covers the method, and cleaning acrylic machine guards covers guards in a workshop. Note that coated sheet must not be polished: polishing removes the coating.
Telling us about a scratch requirement
AcrylicFabWorks, the acrylic division of SinoPlastix, cuts, machines, bends, bonds and polishes acrylic in one ISO 9001 plant in Suzhou, China, using Calypto cast acrylic sheet, cast on the same site, or branded PMMA when your specification names one. If your part needs a hard-coated grade, put the test method and pass mark on the RFQ; the quotation states the exact material and its source, and we flag any bend, bond or print on the drawing that the coating would not survive. If a protective design or film will do the job, we suggest it at drawing review.
FAQ
Is there scratch-resistant acrylic?
Yes. Hard-coated, or abrasion-resistant, acrylic has a cured coating on one or both faces that resists wiping and abrasion much better than standard sheet. It cannot usually be bent or thermoformed without damaging the coating.
Is cast acrylic more scratch-resistant than extruded?
Not meaningfully. Standard cast and extruded acrylic have similar surface hardness. A hard coating or a protective design makes far more difference.
How do I specify scratch resistance for acrylic?
Name a test and a pass mark: a minimum pencil hardness to ASTM D3363, a maximum haze increase after Taber abrasion to ASTM D1044, or a steel wool rub test with stated grade, load and strokes.
Can hard-coated acrylic be polished if it gets scratched?
No. Polishing removes the coating. Scratched coated parts are usually replaced, which is why replaceable cover sheets are worth considering on high-wear parts.
Need a part that stays clear?
Send the drawing and how the surface is cleaned or handled. We reply within 12 hours.
Or email [email protected]