Broach lubrication is crucial to tool life and the quality of the finish produced. Lubrication enables chips to slide freely and curl in the tooth gullets minimizing frictional heat. This cuts down on Broach wear and prevents build up on the cutting edge of the teeth. Push-Type Keyway Broaches, regardless of the material to be broached, require lubrication on the back side of the Broach in order to reduce friction. Proper lubrication will increase Broach life and produce a cleaner finish.
Various materials require different lubricants. duMONT Minute Man® recommends the following:
Mild Steel – A good quality cutting oil or water soluble coolant brushed on the teeth and back side of the Broach.
Tough Steels such as Nickel Alloys – A good grade of a sulfur based cutting oil.
Brass – Typically is broached dry.
Bronze – Works well with an oil or soluble oil.
Cast Iron – Is almost always broached dry, but requires lubrication for the backside of the Broach.
Aluminum – Straight Kerosene may be used, but special lubricants are available.
You may wish to contact your cutting fluid dealer for additional recommendations and availability.