This is American Pneumatic Tool part number 2593 retainer – 7/8 x 3-1/4, stocked at Crowder Supply as APT2593. This part keeps the steel captive in the rock drill under repeated impact, so it is inspected at every steel change and replaced on condition rather than on a schedule.

It appears on the 138 Rock Drill breakdown. Pull up the diagram and confirm the reference number for your serial before ordering.

Everything else on that machine is one page away on the parts diagram hub; complete tools are on the American Pneumatic catalog. Denver stock, with same-day shipment on in-stock orders in by 4 PM ET.

• Part number: 2593
• Manufacturer: American Pneumatic Tool
• Crowder SKU: APT2593
• Listed on breakdowns for: 138 Rock Drill