This is Atlas Copco part number 9245998743 O-Ring – cylinder, stocked at Crowder Supply as AC-9245998743. The cylinder is the bore the piston runs in, and it sets the working clearance of the tool once the bore opens up, air bypasses the piston and blow energy drops.

Give us the model and serial off your machine and we will confirm the fit; the parts diagram hub and the Atlas Copco tool range are the other two places to start. Ships from our Denver warehouse; in-stock parts ordered by 4 PM ET go out the same day.

• Part number: 9245998743
• Manufacturer: Atlas Copco
• Crowder SKU: AC-9245998743