PMMA (Acrylic)
Transparent rigid plastic often used as a substitute for glass.
- Common grades
- Cast acrylic · Extruded acrylic · UV-transmitting / optical grades
- Machinability
- Acrylic is the optical plastic: 92% light transmission (clearer than glass) with good UV stability and scratch resistance among plastics.
- Tolerances
- Agreed per grade at DFM: engineering plastics move with temperature and moisture, so critical fits are toleranced feature by feature
- Processes
- CNC milling, CNC turning and 5-axis machining
- Finishes
- Mechanical polishing · Vapor polishing · Annealing
- Certification
- Manufacturer certificate of conformance and lot traceability with every shipment
Machining PMMA (Acrylic)
Acrylic is the optical plastic: 92% light transmission (clearer than glass) with good UV stability and scratch resistance among plastics. Sight windows, lenses, light guides, displays and instrument covers are where PMMA belongs.
It machines to excellent surface finishes with sharp tooling, and machined faces polish back to full transparency: mechanical polishing for flat faces and edges, vapor polishing for complex geometry. Cast acrylic machines and polishes better than extruded and is what we use unless a drawing dictates otherwise.
Acrylic is stiff but brittle: generous radii and annealing keep machined features crack-free. We hold ±0.05 mm on critical features and manage the finishing chain through to optically clear delivery.
Common Grades We Machine
- Cast acrylic - The machining and polishing grade: better thermal stability and clarity for machined parts.
- Extruded acrylic - Economical sheet for simpler flat parts.
- UV-transmitting / optical grades - Specialty formulations for instrument and lighting applications, sourced on request.
Applications by Industry
Surface Finishing Options
- Mechanical polishing - flat faces and edges returned to full transparency.
- Vapor polishing - optical clarity on complex machined geometry.
- Annealing - stress relief that prevents crazing at machined features.
See our surface finishing services for the full range.
Frequently Asked Questions
Acrylic or polycarbonate for a clear part?
Acrylic for clarity, scratch resistance and UV stability; polycarbonate when the part must survive impact. Displays and optics favour PMMA; guards favour PC.
Can machined acrylic really be optically clear?
Yes. machined surfaces polish back to transparency, mechanically on accessible faces and by vapor polishing on complex forms. Original cast faces are protected through machining wherever possible.
Why do acrylic parts sometimes craze after machining?
Residual machining stress plus solvent contact: including some cleaners and adhesives. We anneal parts and advise on compatible cleaning to keep them crystal clear in service.
Precision PMMA (Acrylic) Manufacturing in Singapore
Need complex PMMA (Acrylic) parts manufactured to tight tolerances? Explore our 5-axis simultaneous CNC machining, CNC milling, CNC turning and certified ISO Class 6–8 cleanroom assembly capabilities.
Speak with Our Sales & Engineering Team
Explore how Shine's Singapore precision CNC machining and cleanroom assembly integrate into your global supply chain. We welcome technical consultations, mutual NDAs, and facility audits.
- Mutual NDA executed within 24 hours
- ISO 9001:2015 certified & Cyber Essentials mark
- 24–48h engineering DFM feedback & formal RFQ pricing