SECTION 5.7

An undercut of the face angle radius can cause the chips to pack in the gullet. Usually, when one chip sticks the subsequent chips will also stick, and the gullet will soon become solidly packed. Since there is then no room for more chips, damage will occur. The damage usually appears in the form of broken teeth, with the damage being one tooth, a whole row of teeth, or even a broken broach.

If tooth damage is not too severe, sometimes it is possible to weld a broken tooth and reconstruct it. This is a high risk process since the extreme heat produced by the welding process can soften or crack the broach tool. A much safer method is the elimination of the entire broken tooth and then re-stepping and tapering the teeth following the damaged section. If an entire section of teeth has been broken (on a slab-type broach), a new section can be either bolted or silver soldered into place, and new teeth can be added. As stated earlier, the repair cost must be weighed against the life left in the damaged tool and the cost of a replacement tool.