Delivering Fluid Sealing Solutions Since 1972

Kalrez® O Rings and Seals

Vast Collection Of Kalrez® O Rings From UK Stock

M Barnwell Services is one of the UK’s leading independent Dupont™ Kalrez® O Rings and Seals providers. Our Dupont™ Kalrez® O Rings, seals, and gaskets offer exceptional heat resistance and chemical stability against 1,800+ chemicals, making them a versatile and high-performance elastomer choice. Their durability presents a cost-effective Metal O Ring alternative without compromising strength or reliability.

Popular Stocked Dupont™ Kalrez® O Rings and Seals we supply:

  • Kalrez 7075: 75 Shore A, Min Temp -20° C / -4°F, Max Temp 327°C / 620°F, Black
  • Kalrez 4079: 75 Shore A, Min Temp -19° C / -2°F, Max Temp 316°C / 600°F, Black
  • Kalrez 6221: 70 Shore A, Max Temp 260°C / 500°F, White
  • Kalrez 6375: 75 Shore A, Min Temp -20° C / -4°F, Max Temp 275°C / 527°F, Black
  • Kalrez 6380: 80 Shore A, Min Temp -22° C / -8°F, Max Temp 225°C / 437°F, Cream
  • kalrez 7090: 90 Shore A, Min Temp -26° C / -15°F, Max Temp 325°C / 617°F, Black
  • Kalrez 0040: 70 Shore A, Min Temp -42° C / -44°F, Max Temp 220°C / 428°F, Black
  • Kalrez 0090: 95 Shore A, Min Temp -21° C / -6°F, Max Temp 250°C / 482°F, Black
  • Kalrez 7777, 7797, 7800: 75/90/75 Shore A, Max Temp 325°C / 617°F, Black
  • Kalrez 1050LF: 82 Shore A, Max Temp 288°C / 550°F, Black

Our skilled team aids in all production stages – from material and size decisions to prototyping, testing, and final manufacturing. M Barnwell Services and its manufacturing partners ensure batch traceability for diverse applications. Contact the team today.

Kalrez® O Rings and Seals

What sets Dupont™ Kalrez® O Rings and Seals apart?

  • Chemical processing temperature range: up to 326° C.
  • Prolonged protection against swelling and embrittlement in harsh, abrasive settings.
  • Oil and gas industry applications temperature range: up to 287° C.
  • Exceptional resistance to corrosion and maintaining durability under elevated temperatures and pressures.
  • Food and pharmaceutical application temperature range: up to 260° C.
  • Heat and chemical resistance while safeguarding against contamination. Dupont™ Kalrez® O Rings and Seals adhere to FDA compliance standards.
  • Semiconductor applications temperature range: up to 325° C.
  • Remarkable chemical resilience and thermal stability.
  • A hardness of 75 for standard products and range from 82 to 95 for specialty products.

Engineered for top-tier performance, Dupont™ Kalrez® elastomer components have been a favored FFKM choice for three decades. Noteworthy benefits encompass:

  • Enhanced productivity.
  • Lower maintenance expenses.
  • Sustained process purity.
  • Heightened safety.


Alongside Dupont™ Kalrez® O Rings and Seals, we also offer a comprehensive range of other quality FFKM materials including Perlast®, Simriz™, Elast-O-Lion®, Parofluor®, Kalrez®, Chemraz®, Isolast®, Ekraz®, Kaflon™ and Valqua (Armor, Fluoritz). Visit the FFKM material page to learn more.

If you would like more information about our range, download our catalogue, or contact a team member.

Explore the provided links for precise technical information to guide your fluid sealing choices.

If you are technical and understand your requirements please use the RFQ Form.

You Are In Safe Hands

As a reliable partner to global OEM manufacturers, M Barnwell Services ensures quality products and an exceptional service experience. With £5.1 million in sealing inventory and five UK branches strategically positioned, we’re primed to meet and surpass your needs.

For additional information about our range, download our catalogue, explore the  Seal Maker Page, or contact our team.

E & OE. M Barnwell Services endeavour to make sure that all content is correct. We have gathered this information from manufacturing partners. (Kalrez® is a trademark of Dupont™ Company. M Barnwell Services does not manufacture Dupont™ products).


Standard O-Rings
Metric O-Rings
JIS O-Rings
Custom O-Rings
Splice & Join O- Rings

Compounds Available

White and Translucent - 5100, 6005, 6221, 6236, 6380, 6880, 7275, 7745, 8002, 8085, 8475, 8575, 9100, 9300, 9400, 9500, 9550, 9600, LS205, 100JX.

Black - 0040, 0090, 3035, 4001, 4079, 6190, 6230, 6375, 6885, 6890, 7075, 7090, 7375, 7390, 7777, 7797, 7800, 8705, 8775, 8900, 8950, CN800, CP222, F798, HEG200, LS222, MS220, OG193, W240.

Other compounds available.


British Imperial (BS1806) and Metric (BS4518). European Metric (ISO 3601), including German (DIN 3771), Swedish (SMS 1586/1588) and French (NFT 47 501). American (SAE, AMS, AS568) and Japanese Metric (JISB 2401), SAE J515 and ISO8434-3 (SAE O ring boss hydraulic adaptors).


M Barnwell Services continuously strives to fulfill customer and application needs. In specific industries, meeting industry criteria is vital. Approvals include WRC, WRAS, FDA, DVGW, KTW, BGVV, KIWA, USP Class VI, NSF, ACS, EU2002/72, EN681-1, EN549, 3A Sanitary, NORSOK, NACE TM0297, NACE TM0187, NORSOK M710, TOTAL GS PVV 142, ISO 23936-2, ISO 10423 API 6A, SHELL SPE 85/301, ISIR, and EN682.

Associated Products

Encapsulated O-Rings (FEP/PFA), Lube, Gauge / O Ring material tester, Quad Rings® (X-Rings) / Nu-lip Rings, O-Ring Cord, Tube, Anti-extrusion Rings, Splicing Kits, Back-up Rings, Anti-extrusion Rings, Lubricants and Adhesives.