Broaching Types and Terms

Types of Broaching

• Gear hobbing is the process of using a broaching machine to cut gear teeth.
• Internal broaching involves using a broach tool to make precise cuts to a preexisting hole on the inside of a workpiece.
  
• Keyseaters are machines that make the keyway holes inside locking mechanisms.
• Rotary broaching, also known as wobble broaching, is a popular broaching method that has been used for years on automatic lathes, and is now gaining popularity on rotary transfer machines and CNC Swiss lathes.
  
• Spline cutting is a broaching process that cuts grooves into the length of a spline shaft.
• Spline shafts have grooves created by broaching machines.
• Surface broaching involves using a broach tool to precisely cut the surface of a workpiece.
  
• Vertical broaches are cutting tools with successively larger teeth.

Broaching Terms

Broach - A metal cutting tool with a series of cutting teeth.

Chip Space - The space between the teeth on a broach that accumulates chips during the cutting operation.

External Broach - A broach that cuts along the external surface of a workpiece.

Face Angle - The angle of the cutting edge of a broach tooth.

Finishing Teeth - Teeth for finishing a surface that are arranged at a constant size at the end of a broach.

Gullet - Another name for "chip space."

Hook Angle - Another name for a tooth's "face angle."

Internal Broach - A broach that is pulled or pushed through a hole in the workpiece in order to bring the hole to a desired size and shape.

Overall Length - The length of a broach tool.

Pitch - The measurement from the cutting edge of one tooth to the same point on the next.

Pull Broach - A type of broach that is pulled through or over the surface of the workpiece during an operation.

Push Broach - A type of broach that is pushed through or over the surface of the workpiece during an operation.

Roughing Teeth - The teeth that cut first in a broaching operation, with heavier cuts than semi-finishing teeth.

Round Broach - A broach with a circular section.

Shear Angle - On surface broaches, the angle between the cutting edge of a shear tool and the line perpendicular to the broach axis or line of travel.

Shear Cutting Tooth - A type of tooth used on surface and external broaches, positioned so that it does not make a right angle with the direction of broach motion.

Surface Broach - An external broach that is used to cut a flat or contoured surface.

Tooth Depth - From the root to the cutting edge, the height of the tooth or broach gullet.