... very high penetration rate .To secure the bit from diameter loss, the gage protection inserts have got shorter length ... Available Size: 6",6 1/2",7 1/2",8 1/2",9 1/2",9 5/8",9 7/8",12 1/4",17 ... 8",6",6 1/2",7 1/2",7 7/8",8 1/2",9 1/2",9 5/8",9 7/8",12 1 ... decibels. Main Type Available Size: 8 1/2",9 1/2",9 5/8",9 7/8",10 5/8",12 1/4 ... 217 226 316 317 326 327 336 337 115 125 135 215 225 235 315 325 335 114 124 ...