We, ZhongYuan Special Steel Co.,Ltd, since1970 , 4200 workers, based on the whole line of steel making, forging, machining, and heat treatment, could produce integral drill collar ,spiral DC , Non-magnetic DC, integral HWDP, stabilizer ,square kelly etc, all licensed under ISO9001:2000 ,ISO14001:2004,GB/T28001-2001 and API monogram . Rotary forging machine, made by GFM, can produce integral bars max 20m length is the most distinguishing featureOur product research, expand, produce, after-sale service are strictly conformed to ISO9001 standards. Competitive price, high efficiency, quality and good service are our principle.Pls kindly visit our website www.zssw.com to get a better idea of our products.