This is American Pneumatic Tool part number 1280583582, listed as 00859 before the renumbering washer – flat, stocked at Crowder Supply as APT859. It spreads clamp load and protects the face under the fastener routine hardware, but the wrong one changes how the joint holds torque.
It shows up in the parts breakdown for the 138 Rock Drill and 155 Rock Drill. Compare it to the reference callout on the diagram to be sure it is the position you need.
If you need the parts around it, the parts breakdown index has the full breakdown library, and the APT lineup covers the machines themselves. Ships from our Denver warehouse; in-stock parts ordered by 4 PM ET go out the same day.
- Part number: 1280583582
- Previous part number: 00859
- Manufacturer: American Pneumatic Tool
- Crowder SKU: APT859
- Listed on breakdowns for: 138 Rock Drill, 155 Rock Drill
