Broaching tools

Initial experience of FHUSA-TSA was about manufacturing POT broaches for external splines and flat broaches for internal keyways. Nowadays, our major activity is about internal spline broaching (often complementing shaper cutter application). However, in the present we have diverse projects both in terms of profile and geometry or material.

Spline internal broaches

Cylindrical broaches are one of the most precise and productive solution for internal splines of any shape. Last broach teeth (finishing rings) are negative profile of desired form. First teeth carry out a progressive roughing from a pre-existing hole. In more complex cases, several passes are necessary to achieve the final profile. It is possible to use finishing shells that allow obtaining two quality classes more than monoblock broaches.

Starting hole can coincide with spline minor diameter; broach would not change minor diameter but can make a chamfer on it (semi-topping). When centring hole is smaller, minor diameter is obtained by round teeth in the finishing section of the broach, assuring concentricity of all diameters.

Sharpening of spur spline broaches is normally straight. However, smoother continuous cut can be achieved with helical sharpening. Finally, broaches for helical spines (spiral broaching) must be helical.