EPDM A90
Hardness band
also Ethylene Propylene Diene Monomer, Nordel
A90 = shore A 90
Rigid rubber for bushings, wheel treads and highly extruded seal geometries.
Values for the A90 condition
Other EPDM grades and fills
EPDM is listed in 12 conditions; see the grade overview at EPDM.
Compare all 12 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
Closed-cell / open-cell cellular EPDM | Pick for low-closure-force dust, water and acoustic sealing (cabinet gaskets, door seals) where compression load must stay low. | — | 2 | 200 | 20 Shore A |
Shore A 40 | Soft grade for low-force conformal sealing on rough or uneven flanges. | — | 8 | 550 | 40 Shore A |
Flame-retardant | Use for rail, cable-accessory and enclosure seals needing UL 94 V-0 or EN 45545 fire performance; ATH loading raises stiffness and cuts elongation. | — | 8 | 250 | 25 Shore D |
Shore A 50 | Compromise durometer for low-pressure static gaskets needing good conformability. | — | 9 | 500 | 50 Shore A |
Carbon-black conductive / semiconductive grade | Highly conductive-black loaded compound for cable semicon layers, EMI/static-dissipative gaskets and grounding pads. | — | 10 | 250 | 25 Shore D |
Shore A 60 | General sheet/extrusion durometer balancing sealing force and abrasion life. | — | 11 | 450 | 60 Shore A |
SolidDefault Dense vulcanized EPDM compound | Default dense rubber for O-rings, gaskets, weatherstrip and hose where a pressure-tight, load-bearing seal is needed. | — | 12 | 400 | 22 Shore D |
Shore A 70 | Industry-default hardness for O-rings and dynamic-pressure static seals. | — | 12 | 400 | 22 Shore D |
Sulfur-cured | Lowest-cost, fastest-curing option for weatherstrip, roofing and general gaskets below ~120 °C. | — | 12 | 420 | 22 Shore D |
Shore A 80 | Use for higher-pressure seals, backup rings and extrusion-resistant profiles. | — | 14 | 300 | 30 Shore D |
Peroxide-cured | Choose for steam, hot water and 150 °C air service, and wherever low compression set or non-staining/low-extractable behaviour is required. | — | 15 | 350 | 22 Shore D |
A90This page Shore A 90 | Rigid rubber for bushings, wheel treads and highly extruded seal geometries. | — | 16 | 200 | 38 Shore D |
What is EPDM A90?
EPDM A90 is EPDM heat treated to A90 — rigid rubber for bushings, wheel treads and highly extruded seal geometries. EPDM A90 has a tensile strength of 16 MPa (2.32 ksi), weaker than 72% of polymer grades. Elongation at break is 200% and the elastic modulus is 0.02 GPa (0.0029 Msi). EPDM A90 has a density of 1.25 g/cm³ (0.0452 lb/in³), heavier than 64% of polymer grades. Its glass-transition temperature is -55°C (-67 °F). Solid is the default condition FabDigit quotes; A90 is available on request or by drawing note.
Advantages
- Good UV / weathering resistance — 95/100, better than 95% of polymer grades
- Conducts heat well — 0.35 W/m·K (0.202 BTU/hr·ft·°F), better than 91% of polymer grades
- Ductile — tolerates forming and impact — 200%, better than 76% of polymer grades
Limitations
- Hard to polish — 20/100, worse than 95% of polymer grades
- Difficult to machine — 40/100, worse than 82% of polymer grades
- High mold shrinkage — 2%, worse than 81% of polymer grades
- Difficult to weld — 12/100, worse than 80% of polymer grades
- Low stiffness — 0.02 GPa (0.0029 Msi), worse than 75% of polymer grades
EPDM A90 properties
Typical room-temperature values for EPDM A90; 17 are specific to this condition. Other listed values are EPDM reference data and may not represent this condition. Bars are the position among polymer grades.
Physical3
EPDM A90 has a density of 1.25 g/cm³ (0.0452 lb/in³), heavier than 64% of polymer grades. Its glass-transition temperature is -55°C (-67 °F).
Mechanical10
EPDM A90 has a tensile strength of 16 MPa (2.32 ksi), weaker than 72% of polymer grades. Elongation at break is 200% and the elastic modulus is 0.02 GPa (0.0029 Msi).
Thermal8
EPDM A90 is rated for continuous service to 120°C (248 °F). It conducts heat at 0.35 W/m·K (0.202 BTU/hr·ft·°F), better than 91% of polymer grades. Thermal expansion is 180 µm/m·K (100 µin/in·°F).
Electrical6
EPDM A90 is an electrical insulator with a dielectric strength of 25 kV/mm (635 V/mil) and a resistivity of 1×10¹² Ω·m.
Chemical & Environmental3
Corrosion resistance is excellent (85/100), better than 65% of polymer grades. UV resistance is excellent.
Sustainability4
Producing a kilogram of EPDM A90 takes about 95 MJ of energy and emits 4 kg of CO₂ — less than 70% of polymer grades. Typical recycled content is 5%.
Manufacturability7
EPDM A90's machinability is fair (40/100, worse than 82% of polymer grades); weldability not recommended (12/100); formability good (65/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with EPDM A90
Is EPDM easy to machine?
Best die-cut, waterjet or knife/CNC-blade cut with soap lubricant; milling and drilling smear and tear unless the part is frozen or a sharp hollow punch is used.
Can EPDM be welded?
Not thermally weldable — join by hot vulcanized splice, uncured tape splice, or cyanoacrylate/CR contact adhesive after abrasion plus primer.
Can EPDM be formed, bent or molded?
Mix on internal mixer/two-roll mill, then extrude profiles or compression/transfer/injection mold and vulcanize ~160–200 °C; sponge grades use chemical blowing agents with a matched slow cure.
What surface finishes work on EPDM?
Surface finish comes from the mold or extrusion die; flash removed by cryogenic deflashing, and paintability/bondability requires corona, plasma or chlorination pretreatment.
EPDM 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 |
|---|---|---|
| ethylene (C2 units)polymer C2 content; high-C2 grades are semi-crystalline | 45 – 75 | 60 |
| ENB diene (5-ethylidene-2-norbornene)cure site for sulfur vulcanization; DCPD/VNB used in some grades | 0.5 – 12 | 5 |
| carbon black (N550/N660)phr on polymer, in the compounded rubber | 20 – 90 | 60 |
| paraffinic process oilphr; oil-extended polymers supplied pre-oiled | 10 – 100 | 50 |
| calcium carbonate / clay fillerphr, cost filler | 0 – 80 | 30 |
| zinc oxide + stearic acidphr, activators | ≈ 6 | 6 |
| sulfur + accelerators or organic peroxidphr, cure system | 1 – 8 | 3 |
| propylene (C3 units)balance of polymer backbone | ≥ 20 (balance) | — |
EPDM A90 — frequently asked
What is EPDM A90 used for?
EPDM A90 is typically used for automotive window and door weatherstrip, roofing membranes, steam and hot-water gaskets, coolant and radiator hoses, sponge sealing profiles for enclosures and HVAC duct and access-panel gaskets. In short: weatherproof rubber.
What is the tensile strength of EPDM A90?
EPDM A90 has a typical tensile strength of 16 MPa (2.32 ksi) — weaker than 72% of polymer grades. Strength varies by condition: see the 12 listed tempers.
Is EPDM A90 easy to machine?
Not especially — machinability is rated fair (40/100, worse than 82% of polymer grades). Best die-cut, waterjet or knife/CNC-blade cut with soap lubricant; milling and drilling smear and tear unless the part is frozen or a sharp hollow punch is used.
Can EPDM A90 be welded?
Not readily — weldability is rated not recommended (12/100). Not thermally weldable — join by hot vulcanized splice, uncured tape splice, or cyanoacrylate/CR contact adhesive after abrasion plus primer.
What surface finishes work on EPDM A90?
Surface finish comes from the mold or extrusion die; flash removed by cryogenic deflashing, and paintability/bondability requires corona, plasma or chlorination pretreatment.
Can EPDM A90 be formed, bent or molded?
Mix on internal mixer/two-roll mill, then extrude profiles or compression/transfer/injection mold and vulcanize ~160–200 °C; sponge grades use chemical blowing agents with a matched slow cure.
What is the maximum service temperature of EPDM A90?
EPDM A90 is rated for continuous use to about 120°C (248 °F), and briefly to 160°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in EPDM A90?
Yes — EPDM A90 is available for injection molding; every part is priced by an engineer rather than instantly. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM D2000 — Rubber Products in Automotive Applications (classification AA/BA/CA/DA lines) — ASTM (2023)
- ASTM D1418 — Rubber and Rubber Latices Nomenclature (EPDM) — ASTM (2022)
- Vistalon EPDM grade and compound data — ExxonMobil Chemical (2023)
- Nordel IP EPDM technical information — Dow (2022)
- Keltan EPDM compounding guides — Arlanxeo (2023)
- ASM Engineered Materials Handbook Vol. 2 — Engineering Plastics/Elastomers — ASM International (1988)
- O-ring and elastomer chemical compatibility / property tables — Parker Hannifin O-Ring Handbook (2021)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.