PMMA-GP
ASTM D788 · JIS K6717 · GB GB/T 8834 · ISO 8257-1 PMMA
PMMA-GP is a general-purpose injection-moulding polymethyl methacrylate pellet grade covered by ASTM D788, JIS K6717 and GB/T 8834, and serves as the baseline acrylic specification before impact, heat or UV modifiers are added.
Reference datasheet — PMMA-GP is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
PMMA-GP grades and fills
PMMA-GP is supplied in 6 conditions, soft to hard.
Compare all 6 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
Impact-modified (rubber-toughened) PMMA | Use when brittle fracture or snap-fit/assembly stress is the failure mode and 2–4× notched impact is worth some clarity and stiffness loss. | 52 | 25 | 70 HRM | |
Flame-retardant grade | Only where a flame rating is mandatory — expect reduced clarity, lower impact and higher cost versus HB base resin. | 60 | 62 | 3 | 88 Shore D |
Light-diffusing grade | Pick for LED luminaire covers needing uniform luminance and LED hot-spot hiding rather than clarity. | 64 | 66 | 4 | 89 Shore D |
High-flow / thin-wall optical molding grade | Pick for light guides, thin lenses and long flow paths where fill pressure and birefringence must stay low. | 66 | 68 | 3.5 | 89 Shore D |
Heat-resistant (high-Tg copolymer) PMMA | Choose for lamp lenses, automotive interiors and parts seeing 90–110 °C where standard GP would distort. | 73 | 75 | 3.5 | 90 Shore D |
Cell-cast sheet | Use cast sheet for machined/laser-engraved parts, aquaria and premium glazing where the highest MW, stiffness and solvent-crack resistance matter. | 74 | 76 | 5 | 92 Shore D |
Supply forms, finishes and certifications
Ways PMMA-GP is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
XT | Extruded sheet/profile grade | Surface finish |
AS | Antistatic / permanent-antistatic grade | Coating |
MED | Medical / food-contact compliant grade | Certification |
OPT | Precision optical grade | Grade option |
UV | UV-stabilized / weatherable outdoor grade | Grade option |
GPDefault | General-purpose clear injection-molding grade | Standard supply |
What is PMMA-GP?
PMMA-GP is a general-purpose injection-moulding polymethyl methacrylate pellet grade covered by ASTM D788, JIS K6717 and GB/T 8834, and serves as the baseline acrylic specification before impact, heat or UV modifiers are added. It gives about 72 MPa tensile strength at 4.5 % elongation with high optical clarity, and related conditions on file include high-flow, high-impact, high-heat, UV-stabilised, optical, diffusing, flame-retardant, anti-static, medical, extruded (XT) and cast (GS) sheet. The polymer is notch-sensitive, crazes in contact with alcohols, ammonia and ester solvents, and needs annealing around heavy machining. Impact-modified (HI) grades or polycarbonate are the usual step up. PMMA-GP 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-GP has a yield strength of 70 MPa (10.2 ksi) and a tensile strength of 72 MPa (10.4 ksi) — stronger than 79% of polymer grades. Elongation at break is 4.5% and the elastic modulus is 3.2 GPa (0.464 Msi).
What is PMMA-GP used for?
- Injection molded lenses
- Signage letters
- Consumer housings
- Automotive light covers
Advantages
- Polishes to a fine finish — 98/100, better than 100% of polymer grades
- Good UV / weathering resistance — 95/100, better than 95% of polymer grades
- High strength — 70 MPa (10.2 ksi), better than 79% of polymer grades
- Easy to machine — 75/100, better than 78% 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 ductility — 4.5%, worse than 75% of polymer grades
PMMA-GP properties
Typical room-temperature values; bars are the position among polymer grades.
Physical6
PMMA-GP 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).
Mechanical17
PMMA-GP has a yield strength of 70 MPa (10.2 ksi) and a tensile strength of 72 MPa (10.4 ksi) — stronger than 79% of polymer grades. Elongation at break is 4.5% and the elastic modulus is 3.2 GPa (0.464 Msi).
Thermal11
PMMA-GP is rated for continuous service to 75°C (167 °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-GP 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-GP takes about 100 MJ of energy and emits 6 kg of CO₂ — less than 61% of polymer grades. Typical recycled content is 0%.
Manufacturability8
PMMA-GP's machinability is very good (75/100, better than 78% of polymer grades); weldability good (65/100); formability very good (70/100).
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-GP is highlighted; hover a dot for its name, or open the interactive family chart.
Working with PMMA-GP
Is PMMA-GP easy to machine?
Machines cleanly with sharp, polished, high-rake carbide tools at high speed and light feed; use coolant/air blast to avoid gumming, anneal (80 °C) before and after heavy cuts to prevent crazing and cracking at drilled holes.
Can PMMA-GP be welded?
Not hot-gas/ultrasonic-friendly for optics — join by solvent cementing (dichloromethane, MMA-based cements) or UV-cure acrylic adhesive; hot-plate and vibration welding are possible for opaque parts.
Can PMMA-GP be formed, bent or molded?
Dry 4–6 h at 80–90 °C to <0.05 % moisture; inject at 220–260 °C melt with 50–90 °C mold, slow fill and high hold pressure for low internal stress; sheet thermoforms at 150–180 °C.
PMMA-GP 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 comonomthermal-stability comonomer in most molding grades | 0 – 8 | 3 |
| processing lubricant / mold releasestearate or fatty alcohol | 0 – 0.5 | 0.2 |
| chain transfer agent residue / antioxida | 0 – 0.3 | 0.1 |
| methyl methacrylate (MMA)polymer backbone | ≥ 90 (balance) |
What surface finishes work on PMMA-GP?
Excellent flame, diamond and buff polishing to optical clarity; accepts hard-coat, anti-reflective and metallizing (vacuum Al) — avoid alcohol/ammonia cleaners and ester-based paints that cause stress crazing.
Equivalent designations
Standards and trade names that resolve to PMMA-GP in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- D788
- ISO
- 8257-1 PMMA
- GB (China)
- GB/T 8834
- JIS
- K6717
How much does PMMA-GP cost?
PMMA-GP is a standard-cost polymer ($$), cheaper than about 71% 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-GP — frequently asked
What is PMMA-GP used for?
PMMA-GP is typically used for injection molded lenses, signage letters, consumer housings and automotive light covers. In short: baseline optical moulding grade; polishes to optical clarity; brittle versus polycarbonate.
What is the yield strength of PMMA-GP?
PMMA-GP has a typical yield strength of 70 MPa (10.2 ksi) and a tensile strength of 72 MPa (10.4 ksi) — stronger than 79% of polymer grades. Strength varies by condition: see the 6 listed tempers.
Is PMMA-GP easy to machine?
Yes — machinability is rated very good (75/100, better than 78% of polymer grades). Machines cleanly with sharp, polished, high-rake carbide tools at high speed and light feed; use coolant/air blast to avoid gumming, anneal (80 °C) before and after heavy cuts to prevent crazing and cracking at drilled holes.
Can PMMA-GP be welded?
Yes — weldability is rated good (65/100). Not hot-gas/ultrasonic-friendly for optics — join by solvent cementing (dichloromethane, MMA-based cements) or UV-cure acrylic adhesive; hot-plate and vibration welding are possible for opaque parts.
What surface finishes work on PMMA-GP?
Excellent flame, diamond and buff polishing to optical clarity; accepts hard-coat, anti-reflective and metallizing (vacuum Al) — avoid alcohol/ammonia cleaners and ester-based paints that cause stress crazing.
Can PMMA-GP be formed, bent or molded?
Dry 4–6 h at 80–90 °C to <0.05 % moisture; inject at 220–260 °C melt with 50–90 °C mold, slow fill and high hold pressure for low internal stress; sheet thermoforms at 150–180 °C.
What is the maximum service temperature of PMMA-GP?
PMMA-GP is rated for continuous use to about 75°C (167 °F), and briefly to 90°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does PMMA-GP cost?
PMMA-GP is a standard-cost polymer ($$), cheaper than about 71% 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.
Sources
- ISO 8257-1/-2 Plastics — Poly(methyl methacrylate) moulding and extrusion materials — ISO (2021)
- ASTM D788 Standard Classification System for Poly(Methyl Methacrylate) Molding and Extrusion Compounds — ASTM (2018)
- Engineered Materials Handbook Vol. 2: Engineering Plastics — ASM International (1988)
- PLEXIGLAS / ACRYLITE moulding compound data sheets — Röhm GmbH (2023)
- ACRYPET PMMA resin grade data — Mitsubishi Chemical (2023)
- CAMPUS plastics database — PMMA moulding grades (ISO 10350 datasets) — CWFG / CAMPUS consortium (2024)
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.