This is Atlas Copco part number 3111005100 rotation chuck – 3/4 x 4-1/4″, stocked at Crowder Supply as AC-3111005100. Retaining the tool steel is its whole job. Worn retention lets the shank hammer against the bore and turns a cheap part into an expensive front head.
You will find it on the diagram for the BBD 12D DS Rock Drill and BBD 15E ET Rock Drill. Check it against the reference number on the diagram first; serial breaks change what fits.
Everything else on that machine is one page away on the parts diagram library; complete tools are on the Atlas Copco catalog. Stocked in Denver orders placed by 4 PM ET ship the same day when the part is on the shelf.
- Part number: 3111005100
- Manufacturer: Atlas Copco
- Crowder SKU: AC-3111005100
- Listed on breakdowns for: BBD 12D DS Rock Drill, BBD 15E ET Rock Drill

