The WMF Group (
www.wmf.com), which was founded in 1853 as Metallwarenfabrik Straub & Schweizer and has been part of the French SEB Group since 2016, has more than 2,200 employees at its Geislingen headquarters and nearby Hayingen facility.
The company undertakes the development and production of high-quality cookware and cooking knives, many of which are made by forming sheet metal blanks, using tools that are manufactured in-house at its own tool shop in Geislingen.
Hans Brühl, part production and tooling technician at WMF, said: “For about 30 different knife models alone, we use between 100 and 150 die tools, each consisting of an upper and a lower tool made of hardened hot-forming steel.
“To guarantee consistently high product quality, the tool makers have to rework the tools after roughly 3,000 strokes.
“This involves precisely milling and removing about 0.5 mm of material — a process that is possible up to 15 times with the dies. In the past, we performed all these milling and finishing operations on an HSC milling machine.
"However, this machine could only accommodate two dies at a time; and as knife production increased, this led to capacity shortages.”
An evaluation process, which included a series of tests to assess contour accuracy, precision and surface quality, as well as the machining time for refinishing, saw a C 22 UP five-axis machining centre from Hermle come out on top.
The machine features a pallet changer, along with 150 pallets.
Axel Spadinger, head of tool engineering at WMF, said: “With the Hermle C 22 UP, we have been able to reduce machining times by 50% — and more when refinishing the dies.
"Since this work is generally carried out at night and over the weekend, we can use the machining centre during the day for all other machining operations.”