Drill collars are available with the following features:
1. Normal Size from 2-7/8” to 11”; All steel bars must be full length heat treatment.
2. Mechanical properties guaranteed to 1.5” below surface at ambient temperature; Enhanced fatigue resistance (threads cold-rolled, pin-relief groove and box bore back); Phos-coated to prevent galling; and Hardbanding is available upon request.
3. The upper radius of the elevator recess is cold-rolled to increase product life. Slip and elevator recesses can be used together or separately. Special drill pipe elevator designs can be supplied for automated handling operations to decrease non-productive time.