Mutual Screw & Supply

0.21" CS X 18.475" ID Buna-N Nitrile O-Rings | AS568-390 | Dash 390 | 70 Durometer | Black (8 / Pkg.)

0.21" CS X 18.475" ID Buna-N Nitrile O-Rings | AS568-390 | Dash 390 | 70 - Main image
$37.87 $51.17 In stock

Buna-N Nitrile o-rings in AS568-390, 18.475" 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: 390
  • Cross-section: 0.21" (5.33 mm)
  • Inner diameter: 18.475" (469.26 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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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 (4.8 / 5 · 5 reviews)

Adam S. ★★★★★

The -40°F low-end rating is exactly why I grabbed these for an outdoor compressor that sits in an unheated shed all winter. Slid into the groove without twisting and the 70 durometer feels solid, not squishy. Seals up clean so far.

Ellie ★★★★★

Replaced a leaking hydraulic cylinder seal with these and the 70 durometer rubber seated perfectly against the housing. They've handled constant 150°F oil without any swelling or hardening over the first few weeks.

Michael ★★★★★

The 18.475-inch inner diameter was spot-on for my application, and the 70-durometer Buna-N feels reassuringly firm but still easy to work into place. With the -40°F rating, I'm confident it'll hold up in my outdoor setup through the winter without cracking.