... X46,X52,X56,X60,X65,X70,X Spiral Welded Oil Drilling Pipes We can produced drilling pipe ... seam linearity testing and visual inspection1) Certificate: API 5DP-0002,API Q1-0964, ISO 9001,ISO 14001,OHSAS ... materials to meet even surpass the requirements of API Specification, heat treatment is on the basis ... are machined by CNC Lathes and inspected with API Spec standard thread gauges. To improve the galling ...