When broaching ordinary structural steel and cast iron, the roughing speed is generally 3-7 m/min, and the finish broaching speed is less than 3 m/min. For difficult-to-machine metals such as high-temperature alloys or titanium alloys, satisfactory results can only be obtained by using cemented carbide or new high-speed steel broaches on a high-speed broaching machine with good rigidity at speeds of 16-30 m/min or higher. Using a helical broaching device, where the helical broach and workpiece undergo relative linear and rotary motion, internal threads, helical spline holes, and helical internal gears can also be broached.
Broaching generally uses cutting fluids with good lubrication properties, such as cutting oils and extreme pressure emulsions. During high-speed broaching, the cutting temperature is high, and chemical cutting fluids and emulsions with good cooling properties are often selected. If an internally cooled broach is used, the cutting fluid is injected under high pressure into each chip groove of the broach, which has a good effect on improving surface quality, reducing tool wear, and increasing production efficiency.
