425 Buna-N O-Ring 10-Pack - 4-1/2\" ID, 5\" OD, 1/4\" Width, 70A Durometer For Sealing

If you need reliable sealing solutions, this 10-pack of Buna-N O-rings is exactly what you're looking for! These O-rings measure 4-1/2 inches inner diameter, 5 inches outer diameter, with a 1/4-inch cross-sectional width - perfect for various industrial, automotive, and plumbing applications. The Buna-nitrile material (often called Buna-N) is known for its excellent resistance to petroleum-based fluids, oils, HFA/HFB/HFC hydraulic fluids, vegetable oils, alcohols, and acids. With a 70A durometer (hardness), they provide the right balance of flexibility and durability for creating solid seals without being too stiff or too soft. The temperature range is impressive too - they work from -30°F (-34°C) all the way up to 250°F (121°C), handling most common operating conditions. These O-rings meet the Aerospace Standard AS568A, which means they're manufactured to precise dimensional standards for consistent performance. The round cross-section creates an effective seal between cylindrical overlapping surfaces in engines, pumps, valves, flanges, and various fluid handling equipment. Just be aware that Buna-N isn't suitable for applications involving acetone, ethers, esters, ozone, or prolonged UV exposure - so avoid using them in ozone-generating equipment, welding areas, or direct sunlight applications. Having 10 in the pack means you've got spares for future projects or replacements. Whether you're maintaining equipment, building projects, or doing repairs, having quality O-rings on hand is always smart, and these Buna-N rings deliver reliable performance across a wide range of common applications.