We take cryptocurrency — so the coins you hold can buy real hardware.Pay in crypto, spend it on real hardware. Free insured shipping worldwide over $399. Plain, unbranded boxes, sent from Germany.Free insured shipping over $399. Your rate is locked for 30 minutes once checkout opens.Rate locked 30 minutes. Every item sealed, serial-checked and covered by a 24-month warranty.Sealed, 24-month warranty.

Saved items Sign in
Black Buna-N O-ring 65 mm ID 3 mm cross-section pack of 25

Zoro Select

Zoro Select O-Ring 65 mm ID 3 mm Buna-N Black PK25

SKU CH-8J54-NWBBD

Pack of 25 Buna-N O-rings with 65 mm inside diameter and 3 mm cross-section for static sealing

  • Reliable sealing across extreme temperatures from -40 °F to 250 °F
  • Medium-hard 70A durometer Buna-N resists compression set
  • FDA-approved material safe for food-contact applications
  • Metal-detectable design aids contamination control on production lines
  • Pack of 25 O-rings with 65 mm inside diameter and 3 mm cross-section

Sealing Performance

These Buna-N O-rings provide a reliable seal for static and dynamic applications within the specified temperature range. The medium-hard 70A durometer balances compression resistance with flexibility for consistent contact. Each ring has a 65 mm inside diameter and 3 mm cross-section for precise groove fitment. The black colour allows quick visual identification during assembly or inspection.

Temperature Stability

The material maintains sealing properties across a broad range from -40 to 250 degrees Fahrenheit without hardening or excessive softening. This stability supports consistent performance under sustained thermal cycling in fluid power systems. Buna-N construction resists common hydraulic oils, water and many aliphatic hydrocarbons encountered in daily operation. The pack contains 25 rings for multiple maintenance cycles or spares.

Build Quality & Compliance

Each ring is moulded to metric dimensions with an actual 71 mm outside diameter for accurate groove fill. FDA-approved material makes the product suitable for food and pharmaceutical contact where regulation requires it. Metal-detectable composition aids contamination control in sensitive production lines without X-ray detectability. The consistent cross-section simplifies installation and reduces the risk of extrusion under pressure.

How it compares

Measured against everything we stock in Bearings, Belts & Drive Components, at today’s prices. Recalculated every night.

Price $8.99
Cheaper than about 90% of the 693 comparable items (median $35.99).

Specifications

Product
Brand nameZORO SELECT

Questions about this item

How much heat can these 70A Buna-N rings handle during continuous operation?

The material is rated from -40 to 250 degrees F, so sustained temperatures within that range will not degrade the seal.

What groove dimensions do I need on my existing flange for a 65 mm ID, 3 mm cross-section ring?

Machine the groove to accept a 65 mm inside diameter and 3 mm cross-section; the resulting outside diameter will be 71 mm.

Will these metric O-rings seal properly in a legacy SAE groove that is close to the same size?

Metric 65 mm ID and 3 mm width differ from common SAE dash sizes, so a legacy groove will not provide the correct compression.

More in Bearings, Belts & Drive Components

Similar items