Broaching / Splining

Broaching / Splining: An Overview

Broaching

Broaching is a machining process that is utilized in both small and large operations. Almost any shape can be broached and the process can be applied to both the internal and external surface of a part. Broaching is typically used to enlarge a circular hole into a larger noncircular shape such as a square or other desired shape. To achieve this broaching effect, a broach (a tool that is comprised of a series of progressively taller chisel points mounted on a single piece of steel) is pulled or pushed against the part material. During the broaching process, the succession of teeth (chisels) comes in contact with the part small portions of material are removed until the desired broached size and shape is achieved.

As implied earlier, the broaching process can be divided into categories: Push Broaching, Pull Broaching, Internal Broaching, and External Broaching.

Splining

Splining is the act of broaching internal and/or external ridges onto a part. A good example: external ridges are broached on a section of the shaft which then mates to an internal spline of a gear. The closer the fit helps to ensure longer part life and helps to ensure that the gear and shaft effectively transfer torque one to another.