O-Rings

Select material based on chemical compatibility, temperature range, and mechanical stress: Nitrile (Buna-N) for general oil and fuel resistance, Viton (FKM) for high temperatures and aggressive chemicals, EPDM for steam and water, silicone for high and low temperature flexibility, and PTFE for extreme chemical resistance; consult a chemical compatibility chart when in doubt

Measure the cross-sectional diameter (thickness) and the inner diameter (ID) of the groove or existing ring; for replacement, measure ID and cross-section accurately with calipers and refer to standard size charts (AS568 for imperial sizes) to match proper nominal size and tolerances

Choose a static or dynamic specification first: harder durometers (e.g., 70A) are common for static seals and higher pressure, while softer durometers (e.g., 30–50A) improve sealing in low-pressure/dynamic applications; ensure groove design and squeeze (compression) follow industry guidelines to prevent extrusion or excessive wear

Store O-rings away from UV light and ozone, keep them in cool, dry conditions, use compatible lubricants when installing, avoid sharp edges during assembly, and inspect periodically for hardening, cracking, or compression set to replace before failure

Yes; common standards include AS568 for SAE imperial sizes, ISO 3601 for metric sizes and tolerances, and ASTM specifications for material properties—use these to verify size, tolerances, and material performance requirements

O-ring packs and small replacement rings are often available at lower prices, while specialty compounds or precision-cut sizes cost more; average category prices cluster in the mid-range (around $80 for assorted kits and larger industrial packs), and choose premium materials (e.g., FFKM, PTFE) when extreme chemical, temperature, or regulatory requirements demand it

Check manufacturer chemical compatibility and temperature tables for the specific elastomer compound, consider exposure concentration and duration, and when uncertain perform a compatibility test or consult technical data sheets to confirm swelling, hardening, or loss of properties will not occur