Value Collection ZMSCH70157 O-ring Dash 157 Nbr 4.5 in Id

Product Description

The VALUE COLLECTION ZMSCH70157 is a Dash 157 Nitrile Butadiene Rubber (NBR) o-ring used to create leak-free seals in hydraulic, pneumatic, and fluid system connections. It measures 4.5 inches inside diameter (ID), 4.688 inches outside diameter (OD), and 0.0937 inches thick, with a round cross section. Rated at 70 Shore A hardness, it performs reliably across a working temperature range of -40 degrees F to 250 degrees F. This is one of the most widely used o-ring elastomers in trade applications, offering strong resistance to petroleum products, solid compression set retention, and good tear and abrasion resistance. Each package contains 25 o-rings.

This o-ring is suited for use in HVAC, plumbing, hydraulic, and fluid power applications where petroleum-based media is present. The NBR compound is compatible with petroleum products including oils, fuels, and hydraulic fluids, making it a standard choice for residential and commercial service work. HVAC technicians, plumbers, and fluid system mechanics commonly install this o-ring when servicing valve bodies, manifolds, pump housings, and fittings that require a reliable static or dynamic face seal. It conforms to SAE and MIL-Spec standards.

Key Features

• 4.5 inches ID x 4.688 inches OD with 0.0937 inches (3/32 inches) cross section thickness
• Nitrile Butadiene Rubber (Buna-N) construction with 70 Shore A hardness rating
• Working temperature range: -40 degrees F to 250 degrees F
• Excellent resistance to petroleum products, oils, and hydraulic fluids
• Round cross section for consistent compression and seal integrity
• Meets SAE and MIL-Spec standards; sold in a pack of 25

Compatibility

Compatible with petroleum products and petroleum-based fluids. Designed for use in systems where Buna-N elastomers are the specified sealing material. Not recommended for exposure to ozone, direct sunlight during storage, or ozone-generating electrical equipment.

Installation Notes

Inspect the sealing groove and mating surfaces for burrs or contamination before installation. Lubricate the o-ring with a compatible fluid or petroleum-based lubricant to ease installation and prevent twisting. Power down or depressurize the system fully before removing or replacing seals. Do not store unused o-rings in direct sunlight or near motors and other equipment that may generate ozone, as this degrades NBR compound over time.