Non-magnetic drill collars are made of low intensity drill collar material combining a special chemical composition and forged by rotary hammer with low permeability and excellent mechanical property. Each drill collar is fully inspected by inspection department and all data obtained are recorded on quality inspection report. API monogram, heat number, OD, thread connection type and size are stamped on recessed mill flats. LUHAI can produce drill collar with length from 10’ to 31’ and OD from 3 1/8” to 11”.