Canrez CRZ-660 vs Kalrez 4079: FFKM Compound Comparison
Verified by Rachel Mayfield, Supply Chain Analyst - April 2026
Canrez CRZ-660 and Kalrez 4079 are both perfluoroelastomer (FFKM) compounds used in chemical, refinery, and process applications. Canrez CRZ-660 vs Kalrez 4079 They share similar chemistry but differ on temperature ceiling, hardness, and intended service. This page compares the two side-by-side and explains when to specify each.
Side-by-side comparison
| Property | Canrez CRZ-660 | Kalrez 4079 |
|---|---|---|
| Manufacturer | Canyon Components | DuPont (Chemours) |
| Compound | CRZ-660 | 4079 |
| Maximum continuous temp | 325°C | 316°C |
| Minimum temp | 0°C | 0°C |
| Hardness | 75 Shore A | 75 Shore A |
| Colour | Black | Black |
| Typical applications | Chemical, refinery, pharmaceutical | Steam, hot amines, ethylene oxide, sour gas, refinery valves, pulp and paper digesters |
When to specify Canrez CRZ-660
Canrez CRZ-660 suits chemical and similar service. Continuous temperature window is 0°C to 325°C, hardness 75 Shore A. Manufactured by Canyon Components.
When to specify Kalrez 4079
Kalrez 4079 suits steam and similar service. Continuous temperature window is 0°C to 316°C, hardness 75 Shore A. Manufactured by DuPont (Chemours).
Limitation: Not recommended for fully fluorinated solvents; cost.
Key differences
- Temperature ceiling: Canrez CRZ-660 runs 9°C hotter (325°C vs 316°C). Specify the higher-rated compound when continuous service is above 316°C.
- Hardness: Both are 75 Shore A, so groove design and squeeze percentage are interchangeable.
- Manufacturer: Canrez CRZ-660 is from Canyon Components; Kalrez 4079 is from DuPont (Chemours). Lead time and UK availability vary by brand.
- Cost: FFKM pricing varies by manufacturer, batch size, and stock position. Both compounds are at the premium end of elastomer pricing (£30 to £500+ per O-ring depending on size).
Get a UK quote on either compound
Related pages
- Canrez CRZ-660 compound details
- Kalrez 4079 compound details
- BS 1806 O-ring size chart
- ISO 3601 metric O-ring sizes
References
- Canyon Components — Canrez CRZ-660
- DuPont (Chemours) — Kalrez 4079
- BS 1806
- ISO 3601
Frequently Asked Questions
Can I substitute Canrez CRZ-660 for Kalrez 4079?
Yes, Canrez CRZ-660 and Kalrez 4079 are both FFKM compounds with overlapping chemical compatibility. Verify your specific fluid against both manufacturers' compatibility tables before substitution. Temperature window, hardness, and certifications may differ.
Which is hotter: Canrez CRZ-660 or Kalrez 4079?
Canrez CRZ-660 has a higher continuous temperature ceiling (325°C vs 316°C, a 9°C difference).
Which costs less: Canrez CRZ-660 or Kalrez 4079?
FFKM compound pricing depends on manufacturer, batch size, certifications, and current stock position rather than headline brand. Both compounds are at the premium end of elastomer pricing. Get current UK quotes on both before specifying.
Where can I buy Canrez CRZ-660 or Kalrez 4079 in the UK?
Both compounds are supplied in the UK by independent FFKM seal specialists carrying multiple manufacturer lines. Lead time is typically 2-5 working days for stock BS 1806 / AS568 sizes, 4-8 weeks for custom-moulded sizes.
References
- Canyon Components — Canrez CRZ-660
- DuPont (Chemours) — Kalrez 4079
- BS 1806
- ISO 3601