Mutual Screw & Supply

0.21" CS X 5.725" ID Buna-N Nitrile O-Rings | AS568-354 | Dash 354 | 70 Durometer | Black (50 / Pkg.)

0.21" CS X 5.725" ID Buna-N Nitrile O-Rings | AS568-354 | Dash 354 | 70 - Main image
$39.78 $56.03 In stock

Buna-N Nitrile o-rings in AS568-354, 5.725" 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: 354
  • Cross-section: 0.21" (5.33 mm)
  • Inner diameter: 5.725" (145.41 mm)
  • Durometer: 70 Shore A
  • Color: Black
  • Temperature range: -40°F to +250°F (-40°C to +121°C)
  • Measurement type: Imperial
  • Pack quantity: 50 per package
Before you pay

Check the method and total at checkout.

When it ships

Allow for processing time as well as the journey to you.

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

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

View policy
If you need a refund

Keep your order number and contact the store to start.

Please contact us for the refund processing timeframe before returning an item.

View policy
Delivery costs

Review the cost for your destination and chosen service.

Standard Shipping · United States: $0.00

Express Shipping · United States: $3.99

View policy
Returning an item

Check the return conditions before sending anything back.

United States · Return window (days after delivery): 30. Return method: By mail. Return postage: Seller pays.

View policy

Customer Reviews (4.6 / 5 · 5 reviews)

Samuel Q. ★★★★★

The 70 durometer hardness feels exactly right for my air line fittings, and the -40°F to +250°F range gives me peace of mind for outdoor equipment. I grabbed the 50-pack and every single ring is uniform with no flashing or rough edges. These seated perfectly and haven’t leaked a drop since install.

Adam ★★★★★

I needed a solid seal for a hydraulic cylinder rebuild, and these Buna-N 354 rings fit perfectly. The 70 durometer feels just right—firm but not brittle. Good value for a 50-pack.

Penelope ★★★★★

The 0.21" cross-section on these o-rings was exactly what I needed to seal a stubborn vacuum chamber flange, and they held tight through a 200°F bake-out cycle.