The INNOHob™ tools feature a cutting edge whose design has been optimised for customer application. To this end, Samputensili technology specialists analyse the customer’s hobbing processes, evaluating component and tool geometry. Depending on the hobbing machine used, experts recommend process parameters that shorten machining time while extending tool life. Process knowledge enables them to calculate the loads occurring in the hobbing process and recommend the ideal cutting edge radii for each combination of chip thickness and cutting speed. The recommended cutting edges are then achieved by using the latest state-of-the-art methods available on the market for cutting edge preparation.

In order to ensure excellent results, precision optical measurements are used to determine the exact geometry and evenness of the cutting edge. A cutting edge designed to suit the process ensures longer service life and an improved component surface.

The possible effects of a very fine surface combined with optimized cutting edge design are shown below. The blue curve shows how wear develops on a cutting tool tooth flank. Wear initially develops at the cutting edge and increases degressively. At a certain level, wear begins to increase linearly. This is referred to as stable wear growth. It is important to ensure that the defined wear limit lies exactly in this zone (represented by the dash line here). Beyond this point, wear increases progressively and can quickly lead to the catastrophic failure of the tool.

Using INNOHob positively impacts the initial development of wear in the degressive range. Fine surfaces offer significantly fewer delicate roughness peaks. This combines with optimised cutting edge design to significantly reduce wear. When the growth of flank wear on INNOHob crosses into the linear range, the curve will hit our set wear criterion considerably later and the tool can produce significantly more components before it needs to be reconditioned.

In addition, Samputensili’s customers also consistently report significant benefits in terms of service life. The use of INNOHob was monitored at a manufacturer of automotive gearing. They were milling a module mn = 1.45 mm 37-tooth gearing made from 16MnCr5. A S390 tool featuring Alcrona Pro coating was used.

The standard tool achieves a service life of around 800 gears between dressings. After switching to INNOHob, the customer now achieves a service life of 1,200 gears in this process, which corresponds to an increase of 50%. Thanks to the longer service life offered by INNOHob, Samputensili helps customers extend tool change-over intervals, as well as significantly reduce tool costs per piece.