Mutual Screw & Supply

0.21" CS X 18.975" ID Buna-N Nitrile O-Rings | AS568-391 | Dash 391 | 70 Durometer | Black (8 / Pkg.)

0.21" CS X 18.975" ID Buna-N Nitrile O-Rings | AS568-391 | Dash 391 | 70 - Main image
$33.52 $54.07 In stock

Buna-N Nitrile o-rings in AS568-391, 18.975" 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: 391
  • Cross-section: 0.21" (5.33 mm)
  • Inner diameter: 18.975" (481.97 mm)
  • Durometer: 70 Shore A
  • Color: Black
  • Temperature range: -40°F to +250°F (-40°C to +121°C)
  • Measurement type: Imperial
  • Pack quantity: 8 per package
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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)

Grace B. ★★★★★

Installed these on a pump manifold where I needed a reliable seal at higher temps, and they held perfectly through several heat cycles. The 0.21" cross-section feels substantial compared to thinner o-rings I've used.

Mia Y. ★★★★★

I needed a 19-inch o-ring for a large hydraulic cylinder, and the 0.21" cross-section fits perfectly into the groove. The rubber feels pliable yet firm, and it sealed on the first try with no leaks.

John ★★★★★

These Buna-N o-rings have a nice, consistent feel, the 70 durometer seems just right for my hydraulic cylinder rebuild. The 18.975-inch inner diameter was spot-on, and they seated perfectly without any distortion.