16 May 2017

Knurling with high accuracy!

Very narrow tolerances can be adhered to if the right knurling technique and tool is applied. But not only that! We have chosen this example, as not only could the narrow tolerances be kept, but also a high profile quality was achieved over large quantities, stainless steel was processed and a conical face was knurled. This example therefore serves to rebute the assertion that “ narrow tolerances are impossible to adhere to with knurling operations”.

Application requirements

At first glance, the application requirements in the example at hand seemed to be difficult to meet: A bushing made of stainless steel with a 3° conical face should be knurled. The knurled shoulder had to be manufactured within the tolerance limit of +/- 0,05 mm. This very high accuracy grade exacted a high process stability during the complete production process.

Application requirements

Application: Knurled cone
Material: 1.4301 (stainless steel with 500-700 N/mm²
tensile strength)
Machine: Star SR20 RII

Special requirements:
• Sharp profile
• Knurled face with a 3° cone
• High accuracy grade due to close work piece

Application optimization

Hommel+Keller’s application technicians found a successful solution for this exacting application: A zeus knurling tool 131-12R, especially developed for the use on swiss type auto lathes and small work spaces, was used for the application. In order to knurl the flat cone, the knurling tool was set at a 3° angle. Due to the integrated set screws, a correct and
precise setting was considerably easier. As Hommel+Keller focuses within the premium product segment on high-quality material and processing, even such small tolerances can be adhered to. The bore and shoulder pin of the knurling wheel are ground providing extra high smoothness of running and a precise and vibration-free processing.

Application parameters

Knurling Tool: 131-12R150404-A
Knurling wheel: No.10 AA 15x4x4 P. 0,5- 90°
Speed rate: Vc = 35m/min
Feed rate: 0,06 mm/rev
Tool life: 1000 pieces / Knruling wheel


The required high dimensional accuracy could be adhered to during the whole operation by using a form knurling tool zeus 131. A high profile quality on the cone was achieved throughout the complete production process.