About Us Hejian Hengji Bit Manufacture Co. , Ltd is located in Hejian , Hebei province.and is Taiwanese bit industry 's emerging enterprises.The company is principally engaged in the development of assorted series of bits , development , production and sales.Hengji company keeps track of the outside sophisticated technology , and built a elastic production line of CNC machining centers chiefly drill bits , established a double-dyed quality assurance system , wide used in the production and management of computer application systems and control systems.Hengji respective drill bits , to ensure wide-cut compliance with all the terms and standards of the American Petroleum Institute API specification , design , manufacturing and production , and to ensure wide-cut compliance with the the API specification requirements and content .