increase the strength that gets department of concrete broach blade, increase impact resistance and durability, get blade to be circular arc form, the sharp angle that get a tip is increased. The bit that place of attached drawing of attached drawing broach shows is the hard alloy that set solder to get pointed twist drill, hard alloy is YG8. To increase the strength of broach blade ministry, increase impact resistance and durability, get blade to be circular arc form, the sharp angle that get a tip is increased. CNC Milling