For many contract manufacturers, price pressure in international competition is a real challenge. Those who manage to produce components more quickly, and therefore more cost-effectively, have the edge when it comes to placing orders, but usually need to amend their production processes. At Harald Kosche GmbH, which is based in Klagenfurt, Austria, they know how to do this successfully. The company used CERATIZIT Project Engineering to reduce the processing time of a component by 55%, and has ultimately converted its entire production process, step by step – with amazing results.
Harald Kosche GmbH and its CEO, Harald Kosche, have been in business for a long time. As a trained CNC production technician, Harald Kosche started working as a plant engineer in 1991. Until 2005, he was CEO of a company that built plants for the production of glass fibre reinforced pipes, with a diameter of up to 4 m, for clients worldwide. But his preference for metalworking led him back to manufacturing technology in 2005, and he has been CEO of Harald Kosche GmbH since 2009. As a traditional contract manufacturer, he serves clients in the fields of mechanical engineering, steel processing, pipe production and electronics, as well as suppliers to the electronics industry. Accordingly, the company's machinery fleet is ideally designed. “Today we have six CNC lathes, four 5-axis milling machines, and a 3-axis milling machine on which we make our various components,” summarises Harald Kosche, before adding: “Another 5-axis milling machine is on its way.” The company also has a wire cutting EDM machine, and surface grinding and cylindrical grinding machines.
For several years now, Harald Kosche and his team of 10 skilled workers have been processing special CNC turning components. These are high-precision tubes, made of stainless steel. “Round, welded tubes are produced from sheet metal strips, in which the rollers for the roll stands have to be highly precise,” explains Kosche. “These rollers have tolerances of plus or minus one hundredth, which we have to meet – and that’s with hardened blanks.” In other words, this means that the Kosche company has to process the rollers, harden them to a hardness of up to 64 HRC, and then rework them. “Processing cubic boron nitride with a hardness exceeding 60 HRC is a real challenge,” says Andreas Schober, a technical support and sales representative from CERATIZIT. “It is difficult to combine hardness, accuracy and surface quality. However, we were able to solve that problem perfectly with CBN inserts for hard machining.” Harald Kosche agrees with this and comments that CERATIZIT is the only supplier in the hard turning sector that can deliver indexable inserts of this quality.
When Harald Kosche was asked by an international customer to produce so-called ‘roller holders’, he found himself faced with yet another challenge, and so turned to his contact at CERATIZIT once again. “The customer's target prices did not match our processing times, so we had to pull out all the stops to reduce our running times.” Andreas Schober remembers: “Mr Kosche asked me about our project engineering, which I had introduced him to a few weeks earlier, and which is ideal for such situations.” Project Engineering is a service offered by CERATIZT that determines individual processing strategies and tool solutions for manufacturing companies, and can be adapted. The tool manufacturer guarantees significantly optimised manufacturing processes, and encourages customers to “Throw down the challenge!”
Harald Kosche did just that, and described the situation to Andreas Schober. “Although the roller holders are actually just holders for rollers used in steel production, the components are pretty extraordinary,” he says with a smile. “They have central oil lubrication, bore holes, through bores or long bore holes for water cooling.” In addition, the parts are made of different cast types, such as cast steel, cast Nirosta, cast stainless steel, or other forged metals, which makes processing even more difficult. Once Andreas Schober had analysed the previous processing strategy in collaboration with the Project Engineering Team, a solution was quickly developed. For this, Harald Kosche had to be open to new technologies and processing strategies. “Andreas Schober recommended new tools that I had never heard of. For example, the universally usable WTX-UNI solid carbide drill, and the CCR high-performance milling cutter high-performance milling cutter, which greatly impressed me. We have achieved our goals, just by using these new tool solutions. We have reduced our processing time from 180 minutes to 56 minutes. In fact, we have more than halved it. That was astonishing.” In addition, Harald Kosche praised the high process reliability and service life of the tools that were required.
Such results inspired Harald Kosche to use the support of CERATIZIT for the next order. This time it was for a so-called “body” – a large-format roller holder. In the past, the Klagenfurt-based company tailor-made these parts for its customers. However, the new tender included 160 parts, and so the competition for this order was correspondingly high. Andreas Schober: “We nearly reached the limits at first, because of the component dimensions of 700 x 400 x 120 mm and the power of the existing machines. We had to do something to achieve the specified processing time, and at the same time identify tools that would not completely overwhelm the machines with their power consumption.”
In the end, they chose SilverLin solid carbide milling cutters. These not only guarantee high stock removal rates and enormous machining volumes, but are also universally usable and easy on the spindle. These properties convinced Harald Kosche to change his processing strategy for these components. “In the past, we mainly processed the body with a cutter head, and used up to 7 tools to do so. But with the new strategy, I only need 3 tools,” states Kosche. These tools are a CCR-UNI end mill (3xD, SL 61 mm) from the CircularLine range, and two SilverLine solid carbide milling cutters – one short (26 mm), and one long (41 mm). Andreas Schober: “With our trochoidal processing strategy and the use of these tools, we can achieve significantly higher removal rates and have therefore been able to reduce the running time by around 70% – from 180 minutes to 56 minutes.”
But what about tool life when working with these loads and high machining volumes? Harald Kosche was also won over by the SilverLine's performance here. With application parameters of VC 160 m/min and fz 0.09 the short SilverLine variant could reliably process 6 components in a processing time of 90 minutes; and in the long variant, 4 components in 100 minutes. “It’s also a difficult material to work with,” adds Kosche. “The milling cutter showed no weaknesses, and smoothed away the flame cut with one cut, without causing any visible damage.” Andreas Schober: “SilverLine has enormous stability at high removal rates and large amounts of field data. Changing conditions do not affect the tool, and the service life is guaranteed.”
Thanks to this process optimisation, Harald Kosche was awarded the contract, and as he recaps: “Compared to before, we not only saved tools and tool costs, but also reduced our processing time for the 160 components by 320 hours in total. That was more than worth it. On the one hand, we were able to secure the order and realise it economically. On the other hand, we were able to use the time saved and free capacity to complete other orders.” Harald Kosche was particularly impressed by the SilverLine milling cutters. “The milling cutters have enormously increased my productivity, and they are impressive thanks to their high process reliability.” Now, without exception, CERATIZIT SilverLine milling cutters are used on all machines with suitable components.