Text Box: When the milling target is too hard and/or too abrasive to be cut in shear with PDC cutters or with TSD cutters then exposed natural diamonds are called for. This mill type has served well in hard scale removal as well as in hard formations. This cutting structure requires more WOB than shear cutting type mills, but is much lower torque and almost impossible to stall. Diamond sizes available in this design are between 1 carat and 14-16 spc. MS Mill