Mutual Screw & Supply

0.21" CS X 0.537" ID Buna-N Nitrile O-Rings | AS568-311 | Dash 311 | 90 Durometer (500 / Pkg.)

0.21" CS X 0.537" ID Buna-N Nitrile O-Rings | AS568-311 | Dash 311 | 90 - Main image
$42.62 $60.03 In stock

Buna-N Nitrile o-rings in AS568-311, 0.537" inner diameter by 0.21" cross-section. Service range -40°F to +250°F (-40°C to +121°C). Also known as NBR, Buna-N, Chemigum, Hycar, Perbunan.

Specifications

  • Product type: O-Ring
  • Material: Buna-N Nitrile
  • AS568 dash size: 311
  • Cross-section: 0.21" (5.33 mm)
  • Inner diameter: 0.537" (13.64 mm)
  • Durometer: 90 Shore A
  • Temperature range: -40°F to +250°F (-40°C to +121°C)
  • Measurement type: Imperial
  • Pack quantity: 500 per package
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Standard Shipping: Handling (business days) 0–1; Transit (business days) 7–15.

Express Shipping: Handling (business days) 0–1; Transit (business days) 7–15.

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Standard Shipping · United States: $0.00

Express Shipping · United States: $3.99

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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 (4.6 / 5 · 5 reviews)

Alexander ★★★★★

I've been hunting for a 90 durometer seal that stays firm in hot oil, and the 0.537" inner diameter is spot-on for my pump rebuilds. These nitrile rings held up fine at 220°F without any softening. 500 in the bag means I won't be reordering for a while.

Nicholas ★★★★★

The 90 durometer on these o-rings made all the difference in my hydraulic repair—they seated firmly without any squish. I've used softer ones before that failed quickly, but these feel like they'll last. Fast shipping had the job done in one afternoon.

Kevin ★★★★★

Ordered these for a rebuild job and the 90 durometer hardness is exactly what I needed for a high-pressure seal. The 500 count box means I’ve got plenty of spares for future projects, and the sizing matches the AS568 spec perfectly.