Value Collection ZMSCH70231 O-ring Dash 231 Buna-n 70A

Product Description

The VALUE COLLECTION ZMSCH70231 is a Dash 231 O-ring made from Nitrile Butadiene Rubber (Buna-N), the most widely used elastomer in industrial and fluid-system sealing applications. This ring measures 2.625 inches inside diameter, 2.875 inches outside diameter, and 0.125 inches thick with a round cross section. Shore hardness is 70, placing it in the hard hardness rating category. The Buna-N compound delivers excellent resistance to petroleum-based fluids, good compression set performance, and strong tear and abrasion resistance — making it a dependable choice for hydraulic, pneumatic, and fuel-system sealing across HVAC, plumbing, and general mechanical trades.

This O-ring is suited for static and dynamic sealing applications involving petroleum products, oils, fuels, and hydraulic fluids. The Dash 231 designation follows standard AS568 sizing, allowing straightforward cross-referencing and replacement in grooved-face, radial, or piston sealing configurations. Operating temperature range spans -40 degrees F to 250 degrees F, covering most residential and light commercial mechanical system environments. Installers should avoid storing Buna-N O-rings in direct sunlight or near motors and other electrical equipment that may generate ozone, as ozone accelerates elastomer degradation. This item is sold in a package quantity of 50 rings.

Key Features

• Buna-N (Nitrile Butadiene Rubber) construction with excellent petroleum-product resistance
• Dash 231 standard sizing: 2.625 inches ID x 2.875 inches OD x 0.125 inches thick
• 70 Shore A durometer hardness — hard rating for reliable compression set performance
• Operating range of -40 degrees F to 250 degrees F
• Round cross section for consistent groove seating and load distribution
• Meets SAE and MIL-Spec standards

Compatibility

Compatible with petroleum products, oils, fuels, and hydraulic fluids. Designed as a standard AS568 Dash 231 replacement O-ring for use in hydraulic, pneumatic, plumbing, and HVAC fluid-handling systems where Buna-N elastomer is specified. Not FDA approved.

Installation Notes

O-rings are typically installed by plumbers, HVAC technicians, and hydraulic system mechanics. Before replacing an O-ring, relieve all system pressure and isolate the fluid supply. Lubricate the O-ring with a compatible fluid or grease prior to installation to reduce the risk of tearing during seating. Inspect the mating groove for nicks or corrosion that could compromise the seal after installation.