Founded in 2002, Shandong Zhiheng Vibration Damping Tech. Co., Ltd.(formerly Shandong Ningjin Spring Co., Ltd.) is an assigned manufacturer by the Chinese Ministry of Railways. The production code is DNJ. We specialize in all kinds of cold and hot coiled springs with diameter ranging from 0.1mm to 90mm, especially railway, engineering and mine mechanism and vehicle springs. Our main products include compression springs, extension springs, heavy duty extension springs, precise extension ...   |