Kalrez 0040 FFKM O-Ring: Compound, Equivalents, UK Suppliers

25 April 2026

Verified by Rachel Mayfield, Supply Chain Analyst - April 2026

Kalrez 0040 is a 70 Shore A perfluoroelastomer (FFKM) manufactured by DuPont (Chemours). It seals continuously to 250°C and is specified for aerospace fuels and similar service. Low-temp-capable FFKM.

Specifications

PropertyValue
Compound0040
ManufacturerDuPont (Chemours)
Maximum continuous temperature250°C
Minimum temperature-25°C
Hardness70 Shore A
ColourBlack
Material familyLow-temp-capable FFKM

Where Kalrez 0040 is used

Kalrez 0040 is specified for: Aerospace fuels, low-temp chemical service.

Kalrez 0040 equivalents from other FFKM manufacturers

If Kalrez 0040 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 compoundManufacturerMax tempHardnessDirect match
Chemraz 505Greene Tweed230°C75 Shore A

Available O-ring sizes

Kalrez 0040 is supplied in:

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

Kalrez 0040 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

  1. DuPont (Chemours) — Manufacturer
  2. ISO 3601 O-ring sizes
  3. BS 1806

Frequently Asked Questions

What is Kalrez 0040 used for?

Kalrez 0040 is a 70 Shore A FFKM (perfluoroelastomer) compound from DuPont (Chemours). It is used in Aerospace fuels, low-temp chemical service. Continuous service temperature: -25°C to 250°C.

What is the temperature rating of Kalrez 0040?

Kalrez 0040 has a continuous service temperature range of -25°C to 250°C. Short-term excursions above the maximum are possible but degrade service life.

What is the equivalent of Kalrez 0040?

Direct equivalents to Kalrez 0040 include: Chemraz 505. Always confirm chemical compatibility against your specific fluid before substitution.

How much does Kalrez 0040 cost?

FFKM O-rings such as Kalrez 0040 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 Kalrez 0040 in the UK?

Kalrez 0040 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