Bimetal screw barrel, or bimetallic screw barrel are made of two metals or two alloys of metals and mostly coated with extra layer of carbides and other commercial coating material. Bimetallic screw barrel are not different type of screw barrel, like advanced designing etc. A same design screw can be made in Nitrided way and Bimetallic way. For bimetallic barrels, centrifugal casting or rotocasting technology is typically used to cast thin-walled cylinders. It is chiefly used to manufacture rotationally symmetric stock materials in standard sizes for further machining, rather than shaped parts tailored to a particular end-use. For bimetallic screws, we us PTA (Plasma Transferred Arc) automatic alloy spaying technology, especially for precise requirement of screws. Comparing to traditional manual alloy spraying, PTA has better performance with the stability and outlook of screws. -------------------------------------------------- Ningbo Jinyi Precision Machinery Co., Ltd. (since 1992) 158 Qiancheng Road, Zhenhai District, Ningbo 315207, China Email: info@jinyiscrew.com www.jinyi-precision.com www.jinyi-machinery.com