Tool life tripled

The turned parts manufacturer Schauerte machines threads in high-alloy, corrosion-resistant Cr-Ni steel much more economically with GFM Shark thread milling cutters from Johs. Boss GmbH & Co. KG, brand JBO.

Wilhelm Schauerte GmbH & Co. KG in Lennestadt employs 140 skilled workers to manufacture turned parts for the automotive industry, general mechanical and apparatus engineering and sanitary engineering. Among other things, tapered Whitworth pipe threads Rp ½″ (14 threads per inch) have to be inserted into components made from the corrosion-resistant, high-alloy steel X2CrNiMo17-12-2 (material no. 1.4404) over a thread length of around 15 mm. Rotary transfer machines produce these components in large series. In the past, the contract manufacturers in Lennestadt used thread milling cutters from different tool manufacturers to mill the threads. However, the tool life and tool life proved to be insufficient. After just under 12,000 threads, the tools were worn out and had to be replaced. This caused frequent downtimes of the highly productive rotary transfer machines.

­ Optimised cutting geometry

The contract manufacturers in Lennestadt now machine much better and more economically with GFM Shark thread milling cutters (D16x41xG14 IK) from JBO (Johs. Boss GmbH & Co. KG). The tools are held in TENDO Turn hydraulic clamping systems (Schunk). The threads are cooled and lubricated with oil during milling.
The cutting edge geometries of the GFM Shark thread milling cutters are carefully matched to hard, corrosion-resistant steel alloys and now ensure significantly longer tool life. The thread milling cutters machine around 30,000 threads at a cutting speed of Vc=100 m/min and a feed per tooth of fz=0.08 mm up to the wear limit. This means that they achieve almost three times the tool life. On the other hand, they reduce the possible cycle time, as they work more productively than the previously used threading tools.

Multiple use

A special feature of the thread milling cutters from JBO ensures that the tools also optimise efficiency when milling threads in components made from high-alloy steels. They have a total usable cutting edge length of 41 mm. This means that they are only partially stressed when milling threads over 15 mm in length. They can therefore be shortened (halved) by around 20 mm (once the wear limit has been reached on the utilised part of the cutting edges). With the remaining part of the usable cutting edges, they then machine a further 30,000 threads until the wear limit is reached. This means that the production technicians at contract manufacturer Schauerte can use GFM Shark thread milling cutters from JBO for a total of 60,000 and sometimes even up to 80,000 threads on their rotary transfer machines. As specialists at Schauerte confirm, this is done reliably and with process security. With these six times the tool life - compared to conventional thread milling cutters in the past - the GFM Shark thread milling cutters from JBO prove that they can produce much more economically with high process reliability. The contract manufacturer in Lennestadt can now reduce its demand and procurement for thread milling cutters to around a third or even a sixth of the quantities previously required.