Drake Manufacturing Services Co. has recently shipped two linear motor 4-axis CNC thread grinders to a Chinese petroleum company manufacturing drilling rigs, pumping units and other oil field equipment. The first machine, a Drake GS:TI-LM 650 High Accuracy Internal Thread Grinder, will grind threads on ring gages for checking API threads. The second machine, a Drake GS:TE-LM 650 High Accuracy External Thread Grinder, will grind threads for API plug gages. Drake fitted the machines with CNC contour dressers for creating complex wheel forms including all API, full radius and gothic arch, acme with crest and root radii or chamfers, as well as a 60 degree buttress and other thread forms. Both machines were programmed on the customer's parts and proved out at the Drake factory in Warren, Ohio, prior to shipment. Changeovers can be accomplished in as little as 15-minutes by simply entering new part parameters into the Drake PartSmart menus in the Fanuc CNC. The machines will be installed by Drake service engineers, and ongoing service will be handled by local trained field service technicians.