Westfield Fasteners Assortment
Imperial O-Rings, NBR 70 Shore
This imperial O-ring assortment contains a comprehensive selection of the most commonly used imperial O-ring sizes, and are manufactured from Nitrile Butadiene Rubber (NBR) with a hardness of 70 Shore A. The assortment is ideal for maintenance engineers, workshops, service technicians and DIY users, providing a convenient selection of replacement seals for hydraulic, pneumatic and general engineering applications.
NBR 70 Shore O-rings offer an excellent balance of flexibility, durability and sealing performance, making them suitable for a wide variety of static and dynamic sealing applications. Figure 1 illustrates the standard imperial O-ring profile.
These O-rings are manufactured from Nitrile Butadiene Rubber (NBR), also commonly known as Buna-N, and have a hardness of 70 Shore A. This medium-hardness material provides an excellent combination of flexibility, resilience and wear resistance, making it one of the most widely used elastomers for general-purpose sealing applications.
NBR exhibits excellent resistance to mineral oils, greases, hydraulic fluids and many petroleum-based products. It also provides good resistance to abrasion and tearing, making it suitable for many static and dynamic sealing applications.
NBR O-rings are not recommended for prolonged contact with aromatic hydrocarbons, esters, ketones or strongly polar solvents. Care should also be taken where exposure to ozone, weathering or high temperatures is expected, as alternative elastomers may provide improved performance under these conditions.
This assortment is suitable for maintenance, repair and overhaul (MRO), automotive servicing, hydraulic equipment, pneumatic systems and general engineering applications where a selection of imperial NBR O-rings is required.
Imperial O-rings are specified by their inside diameter (ID) and cross section (CS), both measured in inches. For example, an O-ring described as 1/2" x 1/8" has an inside diameter of 1/2 inch and a cross section of 1/8 inch.
Many imperial O-rings conform to the AS568 sizing standard and are identified by AS568 dash numbers, each of which corresponds to a specific inside diameter and cross-section combination. This assortment contains a selection of commonly used imperial sizes suitable for a wide range of sealing applications.
- Hydraulic cylinders
- Pneumatic equipment
- Pumps and valves
- Automotive maintenance
- General engineering
- Fluid handling equipment
Type - Imperial O-rings
Material - Nitrile Butadiene Rubber (NBR), 70 Shore A
Size Range - 1/8" x 1/4" to 1-3/4" x 2-1/8"
Approximate Contents - 382 pieces
