Value Collection ZMSCH70203 O-ring Dash 203 Buna-n Pack 100

Product Description

The VALUE COLLECTION ZMSCH70203 is a Dash 203 O-ring manufactured from Buna-N (Nitrile Butadiene Rubber), the most widely used elastomer in fluid sealing applications. This O-ring measures 0.313 inches inside diameter, 0.563 inches outside diameter, and 0.125 inches thick, with a round cross-section profile and a Shore A hardness rating of 70. Buna-N material delivers excellent resistance to petroleum-based fluids, strong compression set performance, and reliable tear and abrasion resistance. This part is installed by HVAC technicians, plumbers, and mechanical tradespeople working on fluid and gas handling systems.

This O-ring is suited for use in residential and commercial applications involving petroleum-based products, hydraulic fluids, oils, and fuel systems. It performs across a wide service temperature range of -40 degrees F to 250 degrees F, making it appropriate for a broad range of HVAC, plumbing, and general mechanical assemblies. Each package contains 100 O-rings, and the minimum order quantity is 1 package of 100 units. Buna-N is not recommended for use with ozone-generating environments, direct sunlight exposure, or near electrical motors that produce ozone.

Key Features

• Buna-N (Nitrile Butadiene Rubber) construction provides excellent petroleum product resistance
• Dash 203 standard sizing: 0.313 inches ID, 0.563 inches OD, 0.125 inches thick
• Round cross-section profile for reliable sealing in standard O-ring grooves
• Service temperature range of -40 degrees F to 250 degrees F
• Shore A hardness of 70 for firm compression and reduced extrusion risk
• Meets SAE and MIL-Spec standards

Compatibility

Compatible with petroleum products including oils, fuels, and hydraulic fluids. Designed as an OEM-style replacement or service O-ring for standard Dash 203 groove applications in HVAC, plumbing, and mechanical systems. Not FDA approved for food-contact applications.

Installation Notes

O-ring installation should be performed by a qualified technician following applicable system service procedures. De-energize and depressurize the system fully before disassembly. Lightly lubricate the O-ring with a compatible fluid or O-ring lubricant prior to installation to reduce the risk of tearing during seating. Avoid storing Buna-N O-rings near motors, electrical equipment, or in direct sunlight, as ozone and UV exposure degrade the material over time.