As a specialist for cold forming, HONSEL manufactures customised solid parts with close tolerances in a wide range of geometries. The specialised manufacturing depth and the 100 % quality control of the produced parts are the hallmarks of the company.
HONSEL bolts, installed in millions of clutch systems worldwide, are a first-class example of this.
The automotive industry accepts only minimal tolerances. Suppliers have to constantly ensure that every product supplied always meets these stringent specifications. Less than 0.07 mm – that is the concentricity tolerance that HONSEL can guarantee the automotive customer. And HONSEL is less tolerant also when it comes to the length: A coil may deviate in length by only +/- 0.05 mm. HONSEL customers appreciate this precision.
During the hardening process „scalings“ occur on the outer side of the bolts, because the glowing hot metal reacts with the air oxygen. These thin residues from the oxidation process can be barrel finished so that the stud has a glossy surface again.
At the same time, barrel finishing reduces the friction coefficient (COF) of the studs – a precondition for longer service lives of the finished products.
As with all other process steps, HONSEL attaches great importance here again to being able to carry out barrel finishing inhouse.
The cold forming process alone changes the starting material in such a way that it becomes harder on its own. But this is generally not enough. The stud is exerted to huge forces when it is installed in the clutch of a motor vehicle. For this reason they have to be hardened so that they become more resistant. But they don’t have to be hardened all over, because if a stud is too hard, it will break during assembly. Partial hardening is the solution. Predefined partial areas are hardened to a precisely defined material depth to a defined degree of hardness. HONSEL has mastered the art of “hardening to the point” so well because this process takes place in-house.
