12.9grade of track bolt and nut,HRC 38-42,170000PSI We are professional manufacture of earthmoving fastener,all of our fastener are made by high grade alloy steel,the surface hardness can reach HRC36-42, There are 10.9,12.9 class of track bolt and nut,plow bolt and nut,segment bolt with nut,wheel bolt and nut.Also we could produce according to your drawing or sample. Except these fastener,we also ...