12.9 grade of track bolt and nut,HRC38-42 8H7504---6S3419,4K7038---7K2017,7H3597--- ... .S.I.There are 10.9,12.9 class of track bolt and nut,plow bolt and nut,segment bolt with ... drawing or sample. Except these fastener,we also can produce pins and locks,bushes for Cat,Komatsu,ESCO,JCB....If you ...