8.8,10.9,12.9 grade of Track bolt,plow bolt,segment bolt and ... manufacture of earthmoving fastener,all of our fastener are made by high grade alloy steel,the surface hardness can reach HRC36 ... is 170,000 P.S.I. There are 10.9,12.9 class of track bolt and nut,plow bolt and ... with us,we will reply you as soon as possible. 12.9 grade of earthmoving bolt and nut