Mutual Screw & Supply

0.21" CS X 3.1" ID HNBR O-Rings | AS568-338 | Dash 338 | 90 Durometer (8 / Pkg.)

0.21" CS X 3.1" ID HNBR O-Rings | AS568-338 | Dash 338 | 90 Durometer (8 / Pkg.) - Main image
$35.8 $55.08 In stock

HNBR o-rings in AS568-338, 3.1" inner diameter by 0.21" cross-section. Service range -40°F to +300°F (-40°C to +149°C). Also known as HSN, Highly Saturated Nitrile.

Specifications

  • Product type: O-Ring
  • Material: HNBR
  • AS568 dash size: 338
  • Cross-section: 0.21" (5.33 mm)
  • Inner diameter: 3.1" (78.74 mm)
  • Durometer: 90 Shore A
  • Temperature range: -40°F to +300°F (-40°C to +149°C)
  • Measurement type: Imperial
  • Pack quantity: 8 per package
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United States · Return window (days after delivery): 30. Return method: By mail. Return postage: Seller pays.

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Customer Reviews (5.0 / 5 · 5 reviews)

Chloe ★★★★★

The 3.1" inner diameter fit my hydraulic cylinder perfectly, and the 90 durometer feels rock-solid without being brittle. Took a beating at 250°F for a week straight and they're still sealing like new, so the HNBR heat range is legit.

Natalie R. ★★★★★

Was skeptical about the 90 durometer being too stiff, but these HNBR rings sealed perfectly on my compressor's discharge valve. They've held up through several 250°F cycles without any softening or leakage.

Ellie ★★★★★

Installed these on a high-temp hydraulic actuator that's been eating standard nitrile rings, and the HNBR material is holding up perfectly so far. The 0.21" cross-section feels robust and the 90 durometer gives them a firm, confidence-inspiring seat. Exactly what I needed for the 300°F range.