Value Collection ZMSCH70345 O-ring Dash 345 Nitrile Buna-n

Product Description

The VALUE COLLECTION ZMSCH70345 is a Dash 345 Buna-N (Nitrile Butadiene Rubber) O-ring with a round cross section, sized at 4 inches inside diameter, 4-3/8 inches outside diameter, and 3/16 inches thick. Rated at 70 Shore A hardness, this O-ring is engineered for sealing applications where exposure to petroleum-based fluids is expected. Its nitrile elastomer compound delivers strong compression set resistance along with solid tear and abrasion resistance, making it a dependable choice for hydraulic, pneumatic, and fluid-handling assemblies. Licensed plumbers, HVAC technicians, and industrial maintenance professionals regularly specify Buna-N O-rings for these service conditions.

This O-ring is suited for residential and commercial applications involving petroleum products, hydraulic oils, fuels, and many common lubricants. It performs across a broad service temperature range of -40 degrees F to 250 degrees F, covering most standard mechanical and fluid-system environments. It is available in a package quantity of 25, which supports bench-stock replenishment for service shops or contractors running multiple jobs. Avoid storing Buna-N O-rings in direct sunlight or near motors and other electrical equipment that may generate ozone, as ozone exposure degrades nitrile compounds over time.

Key Features

• Buna-N (Nitrile Butadiene Rubber) elastomer — the most widely used O-ring material for petroleum-fluid compatibility
• 70 Shore A hardness rating — hard durometer suitable for moderate to high-pressure sealing applications
• Round cross section, 3/16 inches thick — standard AS568 Dash 345 geometry for drop-in replacement fitment
• Service temperature range: -40 degrees F to 250 degrees F
• Excellent compression set, tear, and abrasion resistance for long service life
• Meets SAE and MIL-Spec standards

Compatibility

Designed for use with petroleum products and compatible fluids in hydraulic, pneumatic, and mechanical sealing applications requiring a standard AS568 Dash 345 O-ring. Not FDA approved; not intended for food-grade or pharmaceutical fluid contact.

Installation Notes

O-ring installation should be performed by qualified tradespeople following applicable system shutdown and depressurization procedures before seal replacement. Lubricate the O-ring with a compatible fluid or O-ring lubricant before seating to prevent tearing during installation. Avoid using sharp tools that may nick or cut the elastomer. Inspect the groove dimensions and surface finish before installation to ensure proper sealing.