API oil casing coupling

1OD: from 4 1/2"-13-3/8"

2.Grades:J55, K55, N80, L80 P110

3.Thread:BTC STC LTC

We have implemented stringent quality control tests system to inspect raw materials and examine products in every stage of the production :
*Size and surface inspection
*Non-destructive test
*Thread inspection
*Hydrostatic test
*Drifting test
*Physical and chemical analysis
*Hardness and pressure test