Drill collar manufactured by alloy steel. Heat treated wholly, produced according API 7-1

MAINLY AS FOLLOWING TYPES:
·Ordinary drill collar
·DC with slip groove
·DC with elevator groove
·DC with spiral groove

Length:9.16 or 9.45 M. may produced as required

The non-magnetic DC produced with low cardon Cr-Mn austenitic alloy steel, featured with low magnetic permeability, good mechanical propties, intergranular anti- corrosion chemical composition and anti-abrasion