... . Surface : plain (oil ). black SUYU specialize in producing rail fastening , track spikes are our main products , track bolt ... Tensile strengthYield strengthElongation 800Mpa640Mpa12%As a leading manufacturer of rail fastening in China , SUYU also can produce many ... . Sleeper screw . rail anchor .rail joint bar . tie plate .rail clips ,elastic rail clip .SKL tension clamp .rail shoulder and so on ...