Materials · 星辰 70S
OMS70S
Transparent, ultra-high-purity FFKM for O₂ / F-based plasma etch and deposition — up to 275 °C.
Properties
ASTM methods, stated conditions
- Hardness
- 73 Shore A (ASTM D2240)
- Tensile strength
- 18.1 MPa (ASTM D412)
- Elongation at break
- 242 % (ASTM D412)
- Compression set
- 23 % (ASTM D395 Method B, 70 h @ 250 °C, 25 % deflection, Type B)
- Service temperature
- -10 °C to +275 °C
- Process compatibility
- Dry + Wet
- Seal type
- Static + Dynamic
- Colour
- Transparent
Read the compression set with its condition — 23 % measured at 300 °C tells you nothing about performance at 200 °C. Every figure on this site is published with the temperature and duration it was measured at, so you can compare grades on the same basis.
Typical applications
Ultra-high-purity plasma chambers, slit / pendulum valves, viewports
Comparable grades
Cross-reference
| Grade | Hardness | Service temp. | Comp. set | Why we pair them |
|---|---|---|---|---|
| Kalrez® 6375 | 75 Shore A | −20 to +275 °C | 24 % | Closest match on hardness and upper temperature; broad-spectrum chemical resistance for semiconductor service. |
| Chemraz® 505 | 75 Shore A | −30 to +230 °C | 25 % | Comparable hardness and chemical breadth, but a lower upper temperature limit. |
Parameter-level comparison only — This pairing is drawn from publicly published hardness, temperature and compression-set figures and is a screening aid, not an equivalence claim. Sealing performance depends on your actual media, temperature, pressure, motion and gland design. Validate with a sample before switching an approved part.
Other grades
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