Bolts and nuts are classified according to their hardness. Generally, the bolts and nuts available in Iran are of grade 8.8, which is not suitable for tractor parts and causes a lot of problems and financial losses for the farmer. Realizing this problem, the R&D team of "Shams Group Company", after conducting technical investigations, offered bolts and nuts under the STC brand and with grade 10.9, which is the best choice for tractors.
