Spiral Welded Oil Drilling Pipes 1.OD: 10.3-1219.2mm ... ,X42,X46,X52,X56,X60,X65,X70,X Spiral Welded Oil Drilling Pipes We can produced drilling pipe(API5D, ... spec Q1 quality control system and API Spec 5DP production standard. We have a complete set of inspection process, ... are machined by CNC Lathes and inspected with API Spec standard thread gauges. To improve the galling-resistance during initial ...