R22, R23, R25, R28, R32 mainly focus the stone quarrying Shank Rod

Shank size is 22 x 108mm, and shank end drill rod end connect bit with thread way.Normally R22,R25,R32 for small hole. We manufacture shank end rods in the following threads:R22, R23, R25, R28, R32 mainly focus the stone quarrying such as granite, marble, limestone, sand stone quarries drilling , diameter of hole range from 38mm-50mm at most, Prodrill use the following special heat treament techology to process 

- Carburization is a process used to harden the entire rod surface both internally and externally to 
strengthen and extend the life of the rod. 

- High Frequency Induction is a process where only the thread ends of the rod are hardened to lengthen 
thread life.