straight shank machine reamer GB1132~84 D6~D20 precision class:H7,H8,H9 Material:M2 hss materialstraight shank machine reamer GB1132~84 D6~D20precision class:H7,H8,H9aper shank machine reamer G1133~84 D8~D50precision class:H7,H8,H9shell machine reamer GB1135~84 D25~D100precision class:H7,H8,H9 high quality high speed steel reamer