Optimising drilling at German contract manufacturer

The success of Zerspanungstechnik Mangner GmbH based in Bad Laasphe, Germany, is built on a clear philosophy — targeted investment in optimisation. Drilling operations have become significantly more efficient thanks to a comprehensive tool package from Mapal, comprising 110 TTD replaceable head drills and a large stock of solid-carbide heads.

When Mike Mangner founded the company in a small rented building in 2013, tools were still changed by hand. The business grew rapidly, and just a year later Mr Mangner acquired his current premises and installed the company’s first Hermle machines. Today, as a traditional contract manufacturer, it serves customers primarily in the tool and mould-making industry, offering services such as pressure die casting, sand casting and model-making. Most of the work is destined for the automotive sector, although components for general machine engineering are also produced. Customers come from across Germany, with a strong concentration in the local region.

Pictured right: Mangner mostly uses Hermle machining centres for manufacturing. Programming takes place directly at the machine

The shopfloor currently houses 15 machining centres, predominantly from Hermle, ranging from small five-axis machines to large machining centres capable of handling components up to 1 x 1m. Programming is carried out directly at the operators’ workplaces, with roughly two machines per operator.

Mr Mangner said: “Our optimisation philosophy is based on having many identical machines in operation. The next step in standardisation is to make as many of the same tools available as possible. With this ethos, we are in a strong position and can use our operators in the most flexible way.”

Two years ago, Dominik Geßner joined Mr Mangner as production manager, bringing valuable experience and contacts. Among them was Uwe Rein Geßner, the regional sales manager for www.mapal-os.com/en Mapal. He recommended the use of TTD replaceable head drills, which he had come to trust over the years: “The true advantage of these drills comes into play in hardened materials, which they can machine reliably. We achieve a long tool life here, which reduces our throughput of drill bits.”

Optimal torque transfer
The TTD replaceable head drill is the primary application for Mapal’s TTS (Torque Transfer System) interface. Its stability comes from a radially arranged Hirth serration with 12 or 18 teeth, depending on the diameter of the adapted solid-carbide drill head. This form closure ensures optimal torque transfer, high radial run-out and change-over accuracy. The drill head is secured by a threaded pin on the toolholder, allowing changes directly in the machine. An integrated positioning aid ensures chip flutes and coolant transfer align perfectly. With cutting-edge geometry, the drill head delivers performance comparable to solid carbide drills.

Pictured left: the large tool package from Mapal for Mangner includes a total of 110 TTD replaceable head drills with diameters from 12 to 45mm and lengths of up to 12xD

Previously, bores were made before hardening, requiring an additional clamping step. By eliminating this, set-up time has been reduced and efficiency improved. Mr Mangner noted: “I primarily considered changing the tool system from a cost perspective.” The old system had a weak point: if a solid-carbide drill head broke, the holder was often damaged. Mr Geßner added: “In my experience, this has never happened with Mapal. After breakage, work could always continue with a new drill head, limiting any resulting damage.”

Mr Mangner uses the drills mainly for piloting deep bores and complete bores for cooling, known as coolant boost. While the standard cutting-edge geometry is 140deg, Mapal also offers variants for special applications. A 180deg tip can execute countersink bores that would otherwise require a milling cutter, and ball-nose drills enable radii at the end.

Mr Geßner added: “If handled with care, the drill heads can be reground up to three times by Mapal. This is very sustainable and lowers the average price per tool. We cover a certain diameter range with replacement head drills in increments of tenths. The tools would be unaffordable if made entirely of solid carbide. The Mapal tool package includes diameters from 12-45mm, with lengths of 3xD, 5xD, 8xD and 12xD.”

Typical lot sizes are between one and 10 pieces, with materials ranging from heat-resistant 1.2343 steel to special alloys and aluminium. Following the successful deployment of TTD drills, Mr Mangner and Mapal plan to deepen their cooperation. Reamers are already in use, and test finishing with milling cutters is underway. Mr Geßner believes high-feed cutting could be the next step.