PMMA
also Acrylite, Perspex
PMMA is a rigid, amorphous acrylic thermoplastic prized for the best optical clarity and outdoor weather resistance of the commodity transparent plastics (~92 % light transmission, n≈1.49), with good surface hardness, dimensional stability and easy polishing/solvent bonding.
Values for the Extruded condition
PMMA grades and fills
PMMA is supplied in 8 conditions, soft to hard. Extruded is the default FabDigit quotes; the values on this page are for it.
Compare all 8 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
rubber-toughened acrylic (HI-PMMA / acrylic-impact blends) | Use where clarity is still needed but breakage or notch sensitivity is the failure mode — machine guards, signage, POP displays. | 47 | 50 | 35 | 60 HRM |
FR V-0 | For lighting diffusers, transit glazing and electrical enclosures needing UL 94 V-0 or low smoke; expect some loss of clarity and toughness. | 56 | 58 | 3 | 87 Shore D |
UV-absorber stabilised outdoor grade | For long-life outdoor glazing, signage faces and automotive lenses, or to shield UV-sensitive contents behind the sheet. | 68 | 70 | 4.5 | 89 Shore D |
ExtrudedDefault standard extruded sheet / general purpose grade | Lowest-cost transparent acrylic sheet with tight thickness tolerance; best for thermoforming, laser cutting and signage. | 70 | 4.5 | 92 HRM | |
General-purpose injection-molding pellet grade | Free-flowing pellet grade for thin-wall transparent moldings; dry 4 h at 80 °C before molding. | 70 | 72 | 4 | 90 Shore D |
low-birefringence, high-purity molding/sheet grade | Pick for lenses, light guides, LED optics and display covers where transmission, low haze and low birefringence matter. | 72 | 4 | ||
As cast | Choose for machined and polished parts, thick sheet, chemical exposure and laser-engraved work — higher MW gives better crazing and thermal resistance. | 76 | 4 | 100 HRM | |
Heat-resistant / high-Tg acrylic copolymer | Pick when clarity must survive lamp housings, headlight lenses or autoclave-adjacent temperatures above 100 °C. | 76 | 3.5 |
Supply forms, finishes and certifications
Ways PMMA is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
MED | Medical / food-contact certified grade | Certification |
What is PMMA?
PMMA is a rigid, amorphous acrylic thermoplastic prized for the best optical clarity and outdoor weather resistance of the commodity transparent plastics (~92 % light transmission, n≈1.49), with good surface hardness, dimensional stability and easy polishing/solvent bonding. Cast sheet has higher molecular weight (better machining, chemical and thermal performance) while extruded sheet and injection grades trade some properties for lower cost and formability. Main limits are brittleness (notched Izod ≈20 J/m), stress-crazing in ketones, esters, chlorinated and aromatic solvents or alcohols, and a service ceiling near 70–80 °C. PMMA has a density of 1.19 g/cm³ (0.043 lb/in³), heavier than 53% of polymer grades. Its glass-transition temperature is 105°C (221 °F). PMMA has a yield strength of 68 MPa (9.86 ksi) and a tensile strength of 70 MPa (10.2 ksi) — stronger than 77% of polymer grades. Elongation at break is 4.5% and the elastic modulus is 3.2 GPa (0.464 Msi).
What is PMMA used for?
- Automotive taillight lenses
- Illuminated signage and lettering
- Machine guards and viewing windows
- Light pipes and optical lenses
- Display cases and retail fixtures
- Skylights and architectural glazing
- Instrument panel windows
Advantages
- Polishes to a fine finish — 96/100, better than 99% of polymer grades
- Good UV / weathering resistance — 92/100, better than 93% of polymer grades
- High strength — 68 MPa (9.86 ksi), better than 77% of polymer grades
- Stiff — 3.2 GPa (0.464 Msi), better than 77% of polymer grades
Limitations
- Low fracture toughness — 1.2 MPa·√m (1.09 ksi·√in), worse than 77% of polymer grades
- Limited service temperature — 70°C (158 °F), worse than 77% of polymer grades
- Limited ductility — 4.5%, worse than 75% of polymer grades
PMMA properties
Typical room-temperature values for PMMA-Extruded; bars are the position among polymer grades.
Physical6
PMMA has a density of 1.19 g/cm³ (0.043 lb/in³), heavier than 53% of polymer grades. Its glass-transition temperature is 105°C (221 °F).
Mechanical16
PMMA has a yield strength of 68 MPa (9.86 ksi) and a tensile strength of 70 MPa (10.2 ksi) — stronger than 77% of polymer grades. Elongation at break is 4.5% and the elastic modulus is 3.2 GPa (0.464 Msi).
Thermal11
PMMA is rated for continuous service to 70°C (158 °F). It conducts heat at 0.19 W/m·K (0.11 BTU/hr·ft·°F), worse than 68% of polymer grades. Thermal expansion is 70 µm/m·K (38.9 µin/in·°F).
Electrical7
PMMA is an electrical insulator with a dielectric strength of 25 kV/mm (635 V/mil) and a resistivity of 1×10¹³ Ω·m.
Chemical & Environmental3
Corrosion resistance is very good (80/100), worse than 52% of polymer grades. UV resistance is excellent.
Sustainability4
Producing a kilogram of PMMA takes about 101 MJ of energy and emits 6.4 kg of CO₂ — less than 56% of polymer grades. Typical recycled content is 2%.
Manufacturability8
PMMA's machinability is very good (70/100, better than 74% of polymer grades); weldability good (55/100); formability fair (45/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the polymer family
Yield strength against density for every polymer grade FabDigit runs. PMMA is highlighted; hover a dot for its name, or open the interactive family chart.
Working with PMMA
Is PMMA easy to machine?
Machines cleanly with sharp, polished, high-rake carbide tools and high spindle speed / low feed; use 0° rake or step drills to avoid chipping, and anneal (80 °C, 1 h per 3 mm) before and after cutting to prevent crazing.
Can PMMA be welded?
Not conventionally weldable — join with methylene-chloride or MMA cement (solvent/polymerisable), UV-cure acrylic adhesive, or ultrasonic welding for molded parts; hot-gas/hot-plate welding is possible but leaves visible seams.
Can PMMA be formed, bent or molded?
Thermoform at 150–175 °C from dried sheet; injection mold at 220–265 °C melt / 50–90 °C mold after drying 3–4 h at 80 °C, and hold back pressure to avoid silver streaking.
Manufacturability
The process limits FabDigit's quote engine applies to PMMA. Design inside these and the part quotes instantly; outside them it routes to an engineer.
CNC machining
| Machinability | Better70 / 100 |
|---|---|
| ISO material group | N.8 |
| Cutting speed (rough / finish) | 400 / 500 m/min |
| Minimum wall | 0.5 mm |
| Minimum internal radius | 1 mm |
| Drill depth limit | 10× diameter |
| Best surface (machined / polished) | Ra 0.8 / — |
| Hardenable after machining | No |
Sheet metal
| Formability | Excellent45 / 100 |
|---|---|
| Weldability | Excellent55 / 100 |
Injection molding
| Mold shrinkage | 0.3 – 0.7 % |
|---|---|
| Wall thickness | 0.8 – 4 mm |
| Recommended draft | 1 ° |
| Pre-drying | 80 °C for 4 h |
| UV resistance | Fair |
PMMA chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| methyl acrylate / ethyl acrylate comonomadded in extrusion/injection grades for thermal-processing stability | 0 – 8 | 2 |
| acrylic impact modifier (core-shell rubbonly in impact-modified grades | 0 – 25 | 0 |
| UV absorber (benzotriazole/benzophenone)UV-resistant grades | 0 – 1 | 0 |
| processing aids / release agent / antiox | 0 – 1 | 0.3 |
| methyl methacrylate (MMA)polymerised MMA backbone; homopolymer for cast sheet | ≥ 92 (balance) |
What surface finishes work on PMMA?
Flame, diamond or buff polish gives optical edges; hard-coat lacquers improve scratch and chemical resistance; paints and inks must be acrylic/urethane-based — solvent-rich systems craze the surface.
Surface treatments FabDigit runs on polymer parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Injection Molding Coating
Organic Coating
Metallization / Functional
Equivalent designations
Standards and trade names that resolve to PMMA in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Trade names
- AcrylitePerspexPlexiglascast acrylicextruded acrylicLucitePlexiAcrylicPlexiglass
- Also called
- Polymethyl Methacrylate
How much does PMMA cost?
PMMA is a budget-cost polymer ($), cheaper than about 82% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
PMMA — frequently asked
What is PMMA used for?
PMMA is typically used for automotive taillight lenses, illuminated signage and lettering, machine guards and viewing windows, light pipes and optical lenses, display cases and retail fixtures and skylights and architectural glazing. In short: crystal clear; weatherproof.
What is the yield strength of PMMA?
PMMA has a typical yield strength of 68 MPa (9.86 ksi) and a tensile strength of 70 MPa (10.2 ksi) — stronger than 77% of polymer grades. Strength varies by condition: see the 8 listed tempers.
Is PMMA easy to machine?
Yes — machinability is rated very good (70/100, better than 74% of polymer grades). Machines cleanly with sharp, polished, high-rake carbide tools and high spindle speed / low feed; use 0° rake or step drills to avoid chipping, and anneal (80 °C, 1 h per 3 mm) before and after cutting to prevent crazing.
Can PMMA be welded?
Yes — weldability is rated good (55/100). Not conventionally weldable — join with methylene-chloride or MMA cement (solvent/polymerisable), UV-cure acrylic adhesive, or ultrasonic welding for molded parts; hot-gas/hot-plate welding is possible but leaves visible seams.
What surface finishes work on PMMA?
Flame, diamond or buff polish gives optical edges; hard-coat lacquers improve scratch and chemical resistance; paints and inks must be acrylic/urethane-based — solvent-rich systems craze the surface.
Can PMMA be formed, bent or molded?
Thermoform at 150–175 °C from dried sheet; injection mold at 220–265 °C melt / 50–90 °C mold after drying 3–4 h at 80 °C, and hold back pressure to avoid silver streaking.
What is the maximum service temperature of PMMA?
PMMA is rated for continuous use to about 70°C (158 °F), and briefly to 95°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between PMMA Extruded and PMMA FR?
Extruded is the default condition — lowest-cost transparent acrylic sheet with tight thickness tolerance; best for thermoforming, laser cutting and signage. FR: for lighting diffusers, transit glazing and electrical enclosures needing UL 94 V-0 or low smoke; expect some loss of clarity and toughness. Yield strength is 68 MPa in Extruded versus 56 MPa in FR.
How much does PMMA cost?
PMMA is a budget-cost polymer ($), cheaper than about 82% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Can FabDigit make parts in PMMA?
Yes — PMMA is available for CNC machining, sheet metal and injection molding with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ISO 7823-1/-2 (Poly(methyl methacrylate) sheets — cast and extruded) — ISO (2003)
- ASTM D788 Standard Classification for Poly(Methyl Methacrylate) Molding and Extrusion Compounds — ASTM (2018)
- PLEXIGLAS GS/XT and molding compound datasheets — Röhm GmbH (2023)
- ACRYLITE cast and extruded sheet technical data — Röhm America / Trinseo (2022)
- ACRYPET molding grade technical brochure — Mitsubishi Chemical (2021)
- CAMPUS plastics database — PMMA property profiles (ISO 10350) — CWFG (2024)
- Engineered Materials Handbook Vol. 2: Engineering Plastics — ASM International (1988)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.