Profile: Drill String Services, Inc. specializes in NDT drill pipe inspection and bottom hole assembly (BHA). Our product line includes subs, drill collars, heavy weight drill pipes, and down hole wash tools. Our drill collars are a critical part of bottom hole assemblies. We offer both slick and spiral collars manufactured to meet or exceed current API specifications to assure quality and dependability. Our conventional heavy weight drill pipes provide a gradual transition from heavy drill collars to relatively light drill pipes. This gradual change in weight & rigidity reduces connection fatigue problems, and increases the service life of the drill. The heavy weight drill pipe simplifies directional control in high-angle and horizontal drilling situations, as it bends more easily than drill collars.