O-ring Seal, American Pneumatic Tool part number 1280582685, previously 18740, listed at Crowder Supply as APT18740. It seals a pressure joint inside the tool, and because elastomer takes a set long before the metal around it wears, it is one of the first items to replace when a machine starts weeping air or oil.

Matching it to a machine? Send us the model and serial and we will confirm the fit, or work back from the parts breakdown index. Complete tools are on the American Pneumatic catalog. It ships out of Denver, same day on in-stock orders placed before 4 PM ET.

• Part number: 1280582685
• Previous part number: 18740
• Manufacturer: American Pneumatic Tool
• Crowder SKU: APT18740