Materials
Sakagami Materials — Physical Properties Reference
Physical properties of Sakagami NBR, HNBR, NBR blends, EPDM, FKM, S-KID and polyurethane compounds: hardness, tensile strength, elongation, temperature range and TR10 low-temperature data.
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- 6 min
- Updated
- 2026-07-23
- Published
- 2026-07-23
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- Materials
Physical properties of the elastomer compounds used by Sakagami across their hydraulic, pneumatic and rotary sealing catalogue. Data is taken from the Sakagami material reference and grouped by polymer family for specification and material substitution work.
NBR — nitrile rubber
General-purpose oil-resistant elastomer for hydraulic and pneumatic seals. Broad hardness range (52–87 Shore A) and grades tuned for low friction, low temperature, abrasion or weatherability.
| Material No. | Hardness (Shore A) | Tensile strength MPa {kgf/cm²} | Elongation (%) | Limit temperature (°C) |
|---|---|---|---|---|
| RN503 | 52 | 15.38 {157} | 589 | −35 to 120 |
| RN612 | 62 | 15.48 {158} | 409 | −30 to 120 |
| RN711 | 73 | 14.40 {147} | 233 | −55 to 100 |
| RN712 | 71 | 18.14 {185} | 355 | −30 to 120 |
| RN716 | 71 | 17.65 {180} | 350 | −20 to 120 |
| RN719 | 71 | 18.70 {191} | 310 | −20 to 120 |
| RN722 | 71 | 20.01 {204} | 370 | −30 to 120 |
| RN729 | 70 | 22.66 {231} | 327 | −25 to 120 |
| RN801 | 79 | 23.05 {235} | 312 | −20 to 120 |
| RN803 | 80 | 19.61 {200} | 370 | −20 to 120 |
| RN807 | 79 | 16.48 {168} | 262 | −40 to 120 |
| RN809 | 79 | 15.99 {163} | 136 | −55 to 120 |
| RN812 | 82 | 19.52 {199} | 218 | −45 to 120 |
| RN814 | 78 | 16.77 {171} | 153 | −45 to 120 |
| RN818 | 82 | 23.44 {239} | 239 | −20 to 120 |
| RN819 | 80 | 27.66 {282} | 224 | −25 to 120 |
| RN903 | 85 | 17.26 {176} | 135 | −40 to 100 |
| RN906 | 86 | 20.01 {204} | 220 | −25 to 120 |
| RN909 | 85 | 14.71 {150} | 118 | −55 to 100 |
| RN912 | 87 | 20.59 {210} | 150 | −30 to 120 |
| RN917 | 86 | 20.87 {213} | 180 | −30 to 100 |
| RN919 | 85 | 16.67 {170} | 170 | −30 to 120 |
| RN922 | 85 | 19.71 {201} | 148 | −25 to 120 |
| RN923 | 86 | 21.67 {221} | 169 | −25 to 120 |
HNBR — hydrogenated nitrile rubber
Saturated backbone for higher heat and ozone resistance than NBR while keeping oil compatibility. Preferred for automotive and higher temperature hydraulic duty up to 135 °C.
| Material No. | Hardness (Shore A) | Tensile strength MPa {kgf/cm²} | Elongation (%) | Limit temperature (°C) |
|---|---|---|---|---|
| RP701 | 71 | 19.10 {195} | 230 | −35 to 135 |
| RP703 | 70 | 18.13 {185} | 180 | −35 to 135 |
| RP705 | 70 | 24.30 {248} | 450 | −20 to 135 |
| RP801 | 77 | 24.20 {247} | 270 | −35 to 135 |
| RP805 | 80 | 26.60 {271} | 250 | −20 to 135 |
| RP806 | 82 | 20.80 {212} | 170 | −20 to 135 |
| RP902 | 83 | 21.30 {234} | 140 | −35 to 135 |
| RP903 | 89 | 33.02 {337} | 179 | −20 to 135 |
| RP908 | 84 | 18.00 {184} | 210 | −20 to 135 |
| RP909 | 85 | 15.90 {163} | 96 | −50 to 135 |
NBR blends — NBR + PVC and NBR + EVA
Blended compounds used where weatherability or ozone resistance are needed alongside NBR-style oil resistance. RD902 and RD903 contain PVC; alternative PVC-free grades are available on request as PVC is a regulated substance.
| Material No. | Hardness (Shore A) | Tensile strength MPa {kgf/cm²} | Elongation (%) | Limit temperature (°C) |
|---|---|---|---|---|
| RD902 (NBR + PVC) | 89 | 24.12 {246} | 285 | −25 to 100 |
| RD903 (NBR + PVC) | 96 | 23.24 {237} | 160 | −10 to 100 |
| RD914 (NBR + EVA) | 88 | 18.00 {184} | 200 | −30 to 100 |
EPDM — ethylene-propylene rubber
For water, steam (≤193 °C), brake fluid and polar chemicals. Not compatible with mineral oils.
| Material No. | Hardness (Shore A) | Tensile strength MPa {kgf/cm²} | Elongation (%) | Limit temperature (°C) |
|---|---|---|---|---|
| RE702 | 72 | 16.67 {170} | 224 | −50 to 150 |
| RE703 | 71 | 15.40 {157} | 180 | −45 to 150 |
| RE704 | 72 | 17.10 {174} | 240 | −40 to 150 |
| RE801 | 83 | 14.80 {151} | 150 | −40 to 150 |
| RE901 | 87 | 17.16 {175} | 146 | −50 to 150 |
FKM — fluorine rubber
High temperature and chemical resistance up to 200 °C. Standard grade for aggressive fluids, aromatic fuels and elevated temperature hydraulic service.
| Material No. | Hardness (Shore A) | Tensile strength MPa {kgf/cm²} | Elongation (%) | Limit temperature (°C) |
|---|---|---|---|---|
| RF704 | 71 | 15.20 {155} | 269 | −15 to 200 |
| RF707 | 75 | 17.80 {182} | 430 | −15 to 200 |
| RF807 | 84 | 23.50 {240} | 200 | −30 to 200 |
| RF903 | 85 | 16.67 {170} | 190 | −15 to 200 |
| RF905 | 86 | 17.16 {175} | 190 | −15 to 200 |
| RF907 | 86 | 13.30 {136} | 220 | −15 to 200 |
S-KID NBR and polyurethane
RK703 is a specially formulated nitrile for specific standard figurations. RU803 is a polyurethane rubber used for railway vehicle packings and other high-strength duty.
| Material No. | Hardness (Shore A) | Tensile strength MPa {kgf/cm²} | Elongation (%) | Limit temperature (°C) |
|---|---|---|---|---|
| RK703 (S-KID / specially formulated NBR) | 73 | 14.71 {150} | 256 | −30 to 100 |
| RU803 (Polyurethane) | 85 | 28.12 {287} | 598 | −35 to 100 |
Low-temperature comparison
Sakagami grades suitable for cold service, compared by TR10 — the temperature at which a stretched specimen has retracted 10 % on rewarming. TR10 is a material property limit, not the operating limit of a finished seal.
| Guide temp. | Material | Material No. | Hardness (Shore A) | TR10 (°C) | Use / characteristic |
|---|---|---|---|---|---|
| −30 °C | NBR | RN503 | 52 | -35 | Pneumatic packings (low friction) |
| −30 °C | NBR | RN612 | 62 | -37 | Pneumatic packings (low friction) |
| −30 °C | NBR | RN712 | 71 | -34 | Compatible with JIS B2401 NBR-70-1 (Class 1 A) O-rings |
| −30 °C | NBR | RN722 | 71 | -34 | Standard: MYP; JIS B2401 NBR-70-1 (Class 1 A) O-rings |
| −30 °C | NBR | RN807 | 79 | -31 | Standard: SCB — weatherability |
| −30 °C | NBR | RN917 | 86 | -30 | Standard: 0.5 mm grid-surface gaskets — weatherability |
| −30 °C | NBR | RN919 | 85 | -30 | Standard: GPY, GNY — abrasion resistant |
| −30 °C | S-KID NBR | RK703 | 73 | -34 | Standard: GLY-Z, MYA |
| −30 °C | NBR + EVA | RD914 | 88 | -30 | Standard: 1.0 mm grid-surface gaskets — weatherability |
| −30 °C | HNBR | RP701 | 71 | -32 | Pneumatic packings, auto parts seals (high temp) |
| −30 °C | HNBR | RP703 | 70 | -33 | Pneumatic packings, auto parts seals (high temp) |
| −30 °C | HNBR | RP801 | 77 | -31 | Rotating X-rings, hydraulic valve seals (abrasion) |
| −30 °C | HNBR | RP902 | 83 | -30 | Pneumatic packings, auto parts seals (high temp) |
| −40 °C | NBR | RN812 | 82 | -46 | Standard: SGY — abrasion resistant |
| −40 °C | NBR | RN814 | 78 | -45 | Standard: SCK — high elasticity |
| −40 °C | NBR | RN903 | 85 | -45 | Standard: SKY, KY — low-temperature |
| −40 °C | Polyurethane | RU803 | 85 | -41 | Railway vehicle packings (brakes, door mechanisms) |
| −40 °C | EPDM | RE702 | 72 | -44 | Steam ≤193 °C, brake fluid, chemical resistance, coolant |
| −40 °C | EPDM | RE703 | 71 | -45 | Steam ≤193 °C, brake fluid, chemical resistance, coolant |
| −40 °C | EPDM | RE801 | 83 | -43 | Steam ≤193 °C, brake fluid, chemical resistance; silicone-oil shock absorbers |
| −40 °C | EPDM | RE901 | 87 | -43 | Steam ≤193 °C, brake fluid, chemical resistance, coolant |
| −50 °C | NBR | RN711 | 73 | -59 | Pneumatic packings (low temperature) |
| −50 °C | NBR | RN809 | 79 | -56 | Standard: SNY — high elasticity |
| −50 °C | NBR | RN909 | 85 | -59 | Hydraulic packings (low temperature) |
| −50 °C | HNBR | RP909 | 85 | -50 | Auto parts seals (high elasticity, low temperature) |
Notes
Values reproduced from the Sakagami Physical Properties of Rubber Materials reference. Sealparts can arrange packing and material performance tests on request — contact our technical team for material substitution, cross-referencing or bespoke compound requirements.
Frequently asked questions
- What is the hardness range of Sakagami NBR compounds?
- Sakagami's standard NBR grades run from 52 Shore A (RN503) through 87 Shore A (RN912), covering low-friction pneumatic seals through hard hydraulic backup materials.
- Which Sakagami grade is used for the NMY rod seal?
- RN906 — an 86 Shore A NBR with a service range of −25 to 120 °C, tensile strength around 20 MPa and 220 % elongation.
- Which Sakagami material has the widest temperature range?
- The FKM grades (RF-series) reach 200 °C at the top end. For low temperature, RN711 and RN909 NBR reach TR10 of −59 °C.
Materials
Standards
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