PMMA-HR
JIS K6717 · ISO 8257-3 PMMA-HR
PMMA-HR is a heat-resistant acrylic copolymer, methyl methacrylate polymerised with comonomers such as maleic anhydride or N-substituted maleimide to raise heat deflection temperature above general-purpose PMMA, supplied to JIS K6717.
Reference datasheet — PMMA-HR 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-HR grades and fills
PMMA-HR is supplied in 4 conditions, soft to hard.
Compare all 4 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
Impact-modified heat-resistant acrylic | Choose where snap-fits, thin walls or handling drops would crack standard PMMA; trades stiffness, clarity and HDT for toughness. | 50 | 30 | 60 HRM | |
Flame-retardant compound | Phosphorus/halogen-free FR compound for luminaire and rail-interior parts needing a V-rating; clarity and HDT drop. | 56 | 58 | 3 | 88 Shore D |
Light-diffusing (opal) heat-resistant grade | Contains diffusing particles to hide LED hot spots in luminaire covers while keeping the higher HDT. | 66 | 68 | 3 | 89 Shore D |
Extra-high-heat maleimide copolymer | Pick when the transparent part sees LED/halogen heat above 110 °C and PC yellowing is unacceptable. | 73 | 2.5 |
Supply forms, finishes and certifications
Ways PMMA-HR is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
EXT | Extrusion sheet/profile grade | Supply form |
AS | Antistatic / dust-repellent grade | Coating |
OPT | Optical / low-birefringence lens grade | Grade option |
UV | UV-stabilized / weatherable outdoor grade | Grade option |
NATDefault | Unfilled natural / transparent injection-molding grade | Standard supply |
What is PMMA-HR?
PMMA-HR is a heat-resistant acrylic copolymer, methyl methacrylate polymerised with comonomers such as maleic anhydride or N-substituted maleimide to raise heat deflection temperature above general-purpose PMMA, supplied to JIS K6717. With 74 MPa tensile strength and 3.5 % elongation it is chosen for optical and trim parts that sit close to lamps or in hot vehicle interiors, in moulding pellet and sheet form with IM, UV, OPT, DIFF, AS and FR variants. It stays brittle and notch-sensitive, is not fusion weldable, and stress-cracks in alcohols and esters. PMMA-HI trades the heat rating for impact. PMMA-HR has a density of 1.19 g/cm³ (0.043 lb/in³), heavier than 53% of polymer grades. Its glass-transition temperature is 125°C (257 °F). PMMA-HR has a yield strength of 72 MPa (10.4 ksi) and a tensile strength of 74 MPa (10.7 ksi) — stronger than 82% of polymer grades. Elongation at break is 3.5% and the elastic modulus is 3.3 GPa (0.479 Msi).
What is PMMA-HR used for?
- Automotive interior trim
- LED lighting components
- Headlamp lenses
- Hot-environment glazing
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 — 72 MPa (10.4 ksi), better than 82% of polymer grades
- Stiff — 3.3 GPa (0.479 Msi), better than 80% of polymer grades
- Low, predictable mold shrinkage — 0.45%, better than 77% of polymer grades
Limitations
- Low fracture toughness — 1.1 MPa·√m (1 ksi·√in), worse than 82% of polymer grades
- Limited ductility — 3.5%, worse than 79% of polymer grades
PMMA-HR properties
Typical room-temperature values; bars are the position among polymer grades.
Physical6
PMMA-HR has a density of 1.19 g/cm³ (0.043 lb/in³), heavier than 53% of polymer grades. Its glass-transition temperature is 125°C (257 °F).
Mechanical16
PMMA-HR has a yield strength of 72 MPa (10.4 ksi) and a tensile strength of 74 MPa (10.7 ksi) — stronger than 82% of polymer grades. Elongation at break is 3.5% and the elastic modulus is 3.3 GPa (0.479 Msi).
Thermal11
PMMA-HR is rated for continuous service to 95°C (203 °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 68 µm/m·K (37.8 µin/in·°F).
Electrical7
PMMA-HR 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 (78/100), worse than 61% of polymer grades. UV resistance is excellent.
Sustainability4
Producing a kilogram of PMMA-HR takes about 103 MJ of energy and emits 6.3 kg of CO₂ — less than 54% of polymer grades. Typical recycled content is 0%.
Manufacturability8
PMMA-HR's machinability is good (68/100, better than 71% of polymer grades); weldability good (55/100); formability good (60/100).
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-HR is highlighted; hover a dot for its name, or open the interactive family chart.
Working with PMMA-HR
Is PMMA-HR easy to machine?
Machines cleanly with sharp positive-rake, polished-flute tools and high speed / low feed; use air or mist cooling and anneal (80 °C, 2–4 h) before and after cutting to avoid crazing at drilled holes.
Can PMMA-HR be welded?
Not fusion-welded in practice — join by solvent cementing (methylene-chloride-free acrylic cements are preferred for HR grades), acrylic adhesives, ultrasonic or hot-plate welding of thick sections.
Can PMMA-HR be formed, bent or molded?
Dry 4 h at 80–90 °C to <0.05 % moisture; injection mould at 240–275 °C melt with 70–110 °C tool, moderate injection speed and high hold pressure for optical parts; sheet thermoforms at 165–195 °C.
PMMA-HR 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 |
|---|---|---|
| N-substituted maleimide (e.g. N-cyclohexraises Tg / Vicat; alternative route uses maleic anhydride or glutarimide ring formation | 5 – 25 | 14 |
| styrene / α-methylstyreneoptional comonomer to balance copolymerization and flow | 0 – 10 | 3 |
| methyl acrylatethermal-stability comonomer in some grades | 0 – 2 | 0.5 |
| additives (UV absorber, lubricant, antiograde-dependent | 0 – 1.5 | 0.5 |
| methyl methacrylate (MMA)backbone monomer | ≥ 70 (balance) |
What surface finishes work on PMMA-HR?
Flame-, diamond- or buff-polishes to optical clarity; accepts hard/anti-scratch and AR coatings, vacuum metallization and pad printing — avoid alcohol- or ester-based cleaners which cause stress cracking.
Equivalent designations
Standards and trade names that resolve to PMMA-HR in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ISO
- 8257-3 PMMA-HR
- JIS
- K6717
How much does PMMA-HR cost?
PMMA-HR 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-HR — frequently asked
What is PMMA-HR used for?
PMMA-HR is typically used for automotive interior trim, LED lighting components, headlamp lenses and hot-environment glazing. In short: highest heat acrylic; optical clarity retained hot; low elongation, notch-sensitive.
What is the yield strength of PMMA-HR?
PMMA-HR has a typical yield strength of 72 MPa (10.4 ksi) and a tensile strength of 74 MPa (10.7 ksi) — stronger than 82% of polymer grades. Strength varies by condition: see the 4 listed tempers.
Is PMMA-HR easy to machine?
Reasonably — machinability is rated good (68/100, better than 71% of polymer grades). Machines cleanly with sharp positive-rake, polished-flute tools and high speed / low feed; use air or mist cooling and anneal (80 °C, 2–4 h) before and after cutting to avoid crazing at drilled holes.
Can PMMA-HR be welded?
Yes — weldability is rated good (55/100). Not fusion-welded in practice — join by solvent cementing (methylene-chloride-free acrylic cements are preferred for HR grades), acrylic adhesives, ultrasonic or hot-plate welding of thick sections.
What surface finishes work on PMMA-HR?
Flame-, diamond- or buff-polishes to optical clarity; accepts hard/anti-scratch and AR coatings, vacuum metallization and pad printing — avoid alcohol- or ester-based cleaners which cause stress cracking.
Can PMMA-HR be formed, bent or molded?
Dry 4 h at 80–90 °C to <0.05 % moisture; injection mould at 240–275 °C melt with 70–110 °C tool, moderate injection speed and high hold pressure for optical parts; sheet thermoforms at 165–195 °C.
What is the maximum service temperature of PMMA-HR?
PMMA-HR is rated for continuous use to about 95°C (203 °F), and briefly to 115°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does PMMA-HR cost?
PMMA-HR 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)
- JIS K 6717 Poly(methyl methacrylate) moulding and extrusion materials — JSA (2018)
- ISO 7823-1/-2 Poly(methyl methacrylate) sheets — ISO (2003)
- Heat-resistant acrylic moulding compound datasheets (Röhm Plexiglas hw/8N series, Kuraray Parapet HR, Mitsubishi Chemical Acrypet VH) — various producers (2023)
- CAMPUS plastics database — PMMA heat-resistant grades (ISO 10350-1 datasets) — CAMPUS consortium (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.