Chemraz 526 FFKM O-Ring: Compound, Equivalents, UK Suppliers
Verified by Rachel Mayfield, Supply Chain Analyst - April 2026
Chemraz 526 is a 75 Shore A perfluoroelastomer (FFKM) manufactured by Greene Tweed. It seals continuously to 327°C and is specified for semiconductor processing and similar service. Semiconductor-grade FFKM.
Specifications
| Property | Value |
|---|---|
| Compound | 526 |
| Manufacturer | Greene Tweed |
| Maximum continuous temperature | 327°C |
| Minimum temperature | -10°C |
| Hardness | 75 Shore A |
| Colour | Off-White |
| Material family | Semiconductor-grade FFKM |
Where Chemraz 526 is used
Chemraz 526 is specified for: Semiconductor processing, wet/dry etch, plasma.
Chemraz 526 equivalents from other FFKM manufacturers
If Chemraz 526 isn't available, these compounds from competing manufacturers have similar chemistry and operating windows. Always verify against your actual fluid and temperature before substitution.
| Equivalent compound | Manufacturer | Max temp | Hardness | Direct match |
|---|---|---|---|---|
| Kalrez 7075 | DuPont (Chemours) | 327°C | 75 Shore A | ✓ |
Available O-ring sizes
Chemraz 526 is supplied in:
- BS 1806 sizes: BS001 to BS932 (UK / EU standard, imperial-origin metric)
- AS568 sizes: -001 to -932 (US standard, dimensionally identical to BS 1806)
- ISO 3601 sizes: metric IDs from 2 mm to 670 mm with cross-sections 1.0 mm to 7.0 mm
- JIS B 2401: P, G, S series (Japanese OEM equipment)
- Custom / non-standard: built-to-print for OEM applications
For a list of sizes commonly stocked in the UK, see the BS 1806 size chart, ISO 3601 metric chart, or contact a UK seal specialist below.
UK availability
Chemraz 526 is supplied in the UK by FFKM specialists carrying multiple manufacturer lines. Lead time is typically 2-5 working days for stock sizes, 4-8 weeks for custom-moulded sizes. Use the form below to get a quote from a UK FFKM specialist.
References
- Greene Tweed — Manufacturer
- ISO 3601 O-ring sizes
- BS 1806
Frequently Asked Questions
What is Chemraz 526 used for?
Chemraz 526 is a 75 Shore A FFKM (perfluoroelastomer) compound from Greene Tweed. It is used in Semiconductor processing, wet/dry etch, plasma. Continuous service temperature: -10°C to 327°C.
What is the temperature rating of Chemraz 526?
Chemraz 526 has a continuous service temperature range of -10°C to 327°C. Short-term excursions above the maximum are possible but degrade service life.
What is the equivalent of Chemraz 526?
Direct equivalents to Chemraz 526 include: Kalrez 7075. Always confirm chemical compatibility against your specific fluid before substitution.
How much does Chemraz 526 cost?
FFKM O-rings such as Chemraz 526 are typically £30 to £500 per piece depending on size, with custom or large-bore parts at the upper end. Get a current quote via the form on this page.
Where can I buy Chemraz 526 in the UK?
Chemraz 526 is supplied in the UK by independent FFKM seal specialists with multi-brand inventory. Lead time is 2-5 working days for stock BS/AS568 sizes, 4-8 weeks for custom-moulded sizes.
References
- Greene Tweed — Manufacturer
- ISO 3601 O-ring sizes
- BS 1806