Machining on hard or uneven materials, as well as broaching at high speeds, can damage some or several teeth of the broach, which need to be subjected to functional regeneration so that they can continue to operate accurately.
The main inconveniences to which broaches are subject are the following:
- Wear on cutting edges
- Seized material on the flanks
- Broach breakage
To restore the broach, in cases 1) and 2) it is necessary to take up the rise per tooth and its surface rake, while in case 3) much more complex it is necessary to regrinding the profile of the broach to remove the seized material on the flanks. In the first three cases, the regeneration can still be performed without too many problems, but in the event of tool breakage, it is necessary to first check if repair or any welding is possible.
The most common errors of use that can cause the broach breakage are the following:
1) Broaching hole tight or out of tolerance;
2) Excessive hardness of the pieces;
3) Wrong operation of the broaching machine;
4) Absence or inadequacy of the cutting fluid;
5) In the case of automatic broaching, the lack of specialized personnel to assist broaching and to promptly intervene in case of problems.
If a workpiece gets stuck during broaching, it is advisable to remove it by turning, without forcing it further in an attempt to free it, in order to limit the damage and avoid the risk of breaking the broach.
On request, all types of repair, restoration or modification are carried out in BART, including the construction of new pull end and retriever shanks as well as the deburring of the broaches after resharpening.