Rolling or segmental rolling are effective and economical methods for the chip-less production of rotational symmetrical profiles on the surface, from corresponding workpieces, using cold moulding. Thread rolling is significantly faster, and budget priced in case of a large number of pieces.
Here, the tool profile is transferred to the unmachined piece. In addition to making any kind of threads, wheels with longitudinal grooving are also rolled, as well as serration, and similar profiles. Different kinds of tools and machines are used for this purpose. We distinguish two different production methods:
Mostly, the rolling tool is at least as wide as the rolled profile, and it is rolled over its whole length at the same time; thus, this method is very fast, however, it requires high force, and it is therefore limited in length.
The tool is only as wide as reasonable for the given profile (depending on the gradient), and it has a run-in space, cylindrical space for the profile calibration, and run-out. During rolling, the workpieces are axially transported by tools, so infinite lengths can theoretically be rolled in a segmental manner.
The other advantages of thread rolling are as follows:
- Unlike cutting, the grain boundary are not interrupted
- The surface hardening is achieved by cold moulding
- Polished thread sides by pressing
- Higher resistance against wear
- Reduced cut sensitivity
- No chips, and thus, lower consumption of material
|Size of batches||100 - 100,000 pieces|
|Diameter of parts||Max. 15 mm|
|Range of tolerances||IT6|
|Materials||Aluminium, steel, high quality steel, brass, titanium|
|Options||Recessing method/continuous method|
|Additional machining||Chrome plating, hardening, surface coating, phosphate coating, eloxal coating and laser welding or laser labelling|