... by 40Cr or 35CrMo,hardness HRC38-42 We have 8.8,10.9,12.9 grade of track bolt and nut,plow bolt and ... 's drawing or samples.Grade 8.8 120,000PSI HRC28-34Grade 10.9 150,000PSI HRC34-38Grade 12.9 170,000PSI HRC38-42Track bolt ... any inquiry,please feel free to send here.Thank you ! 8.8-12.9 Grade of track bolt with nut for excavator