Horst Lach, protagonist in the development and application of super-abrasives, celebrated his 64th anniversary at Lach Diamant on October 1st, 2024.
Horst Lach has been known for over six decades as an innovator in the development of diamond tools for the industry and is absolutely recognised as a pioneer. Still, at the age of 85, he is working for his company LACH DIAMANT® every day.
Does LACH DIAMANT present 117 years of expertise and know-how?
Actually, the company was founded only 103 years ago, but as the founder’s son, Horst Lach, recalls “the acquirement of knowledge began already in 1908 when Jakob Lach started his apprenticeship as a diamond cutter.” When wage grinding became unprofitable after World War II, Jakob Lach focused on his second company, which he had founded in the 1930’s for the sale and distribution of industrial diamonds. “Jakob Lach – Industrial Diamonds” [Deutscher Industriediamanten-Vertrieb Jakob Lach] was very successful in the Magdeburg – Leipzig – Chemnitz area (Germany) and well known among automobile manufacturing companies such as Opel in Rüsselsheim (Germany).
With this, a new era had begun for the Jakob Lach company – the name LACH DIAMANT® was born. Dressing and profiling of grinding wheels with industrial diamonds (both set and rough self imported diamonds) became the primary business of LACH DIAMANT in the 1950’s.
Abrasives of a new age
After Horst Lach joined LACH DIAMANT® on October 1st, 1960, the company started manufacturing diamond grinding wheels in metal and resin bond for the grinding of hard metals and ceramics. “The development of metal-coated diamond grits by DeBeers (for example grit type RDA-MC) was instrumental, not only for the success of diamond grinding wheels in resin bond for carbide processing (e. g. LACH DIAMANT®’s grinding wheel K-MC) but also for the development of carbide tools in general”, Horst Lach recollects. “At the same time this paved the way for the commercial success of tool manufacturers such as Leitz, Leuco, Sandvik, Widia and grinding machine manufacturers like Vollmer – Dornhan or Biberach, Walter, Stehle and other companies like them”.
General Electric (GE), a manufacturer of super-abrasives, set another milestone with its introduction of BorazonTM (boron nitride – CBN), a modern day abrasive. “Finally it was possible for tool grinders to accomplish precise circular grinding of HSS milling tools on a Deckel grinder in a one-step process – without having to continuously find new measuring points on a traditional corundum grinding wheel”, Lach comments. The higher temperature resistance of the new abrasive BorazonTM-CBN (up to 1500 ° C) compared to diamond (up to 720 ° C) made this possible despite a low degree of hardness.
The new material revolutionized the industry, and its potential for future processes and applications has still not been fully realized. It is a new material with a great deal of potential for future developments, processing, and applications for the grinding industry, as the presentations at GrindTec demonstrate. LACH DIAMANT® introduced the new “supergrind- power” grinding wheel and “drebojet®-plus”.
At the beginning of the 1970’s everything in the world of tool manufacturers appeared to be “just fine”, as Horst Lach remembers, until two new product innovations by GE shook the industry. These were PCD, a polycrystalline cutting material first introduced in 1973, and in 1974 CBN and PCBn, another polycrystalline cutting materials.
Historically interesting is the fact that GE researchers came across cubic crystalline boron nitride (CBN) early on, during their search for diamond synthesis. However, at that time they did not know what to do with this material since it had such a low hardness compared with diamonds.
Horst Lach remembers that Carboloy in Frankfurt, a GE company, already had CBN blanks in storage during the early 1960’s. Later these blanks were marketed as BZN blanks.
LACH DIAMANT® has been a pioneer from the very beginning – as a matter of fact since the first development, production and commercialization of BorazonTM CBN grinding wheels. “We demonstrated turning of aluminum with interrupted cuts with a new cutting material PCD – dreborid® – at the Hanover Trade Show in 1973.
GE offered polycrystalline synthetic diamond segments with 600 and 900 angles for the first time in 1973. At the time it was very difficult to cut them out of blanks with only 0 3,4 mm, and cutting lengths were equally limited”.
Beastly materials
Grinding these polycrystalline materials was also problematic; diamond cutters, used to grinding natural diamonds, called them “beastly materials” without any structure and they rejected them. LACH DIAMANT® was able to produce the very first PCD lateral turning tool on an existing Simon tool grinding machine with a diamond cup wheel in resin bond (K-MC, 125×12.5) – just in time for the Hanover Trade Show in spring 1973.
“We had a Weiler turning machine with a clamped-on aluminum round part for the following demonstrations. It was covered with bores in order to simulate interrupted cutting. Without knowing an exact tool life, we had ordered one replacement tool per show day (10 days at the time!) from our manufacturing facility in Hanau.
After three days we called off the special driver who transported the tools to Hanover; the PCD cutting edge worked and worked and worked, and at the time we believed we could never wear it down. We only accomplished that on the very last day of the show, when we boisterously placed a small bottle of sparkling wine into the machine… that was the starting point of PCD and the legendary dreborid® at LACH DIAMANT”, describes Horst Lach with a smirk.
LACH DIAMANT® had decades of experience in manufacturing and servicing natural diamonds for the manufacturing companies of copper collectors for the electrical industry, and therefore the company focused at first on those customers, such as Bosch, Siemens, AEG and this strategy proved to be very successful.
“Until then a natural diamond tool for collectors could turn between 100 and 120,000 collectors at the most. PCD dreborid® turning tool made much more economically sound numbers possible. Today, depending on collector size and cut, one tool can produce up to 220,000 collectors.”
Truly electrifying results were achieved when PCD dreborid® was tried out at Kautt & Bux, a manufacturer of rough collectors. Until then rough collectors had to be ground in a time-consuming process. Now this procedure could be done in a few seconds by turning instead of grinding the collectors for several minutes.
This meant for LACH DIAMANT that they had won a key account customer right from the get-go. Both, PCD manufacturing and service could be built on this initial success.
Alternatives on the market for grinding machines
Even diamond cutters of natural diamonds had surrendered to the “beastly” polycrystalline cutting material PCD. New procedures had to be developed and at least some alternative solutions were needed on the market for grinding machines. “Quick decisions were of the essence, since from the very beginning, there were a lot of potential users of PCD, including machining companies who processed aluminum, hard and soft plastics, wooden materials, green ceramics and other materials; the optimal grinding system should not only accomplish straight edges but should also be able to grind angle and radius.
The final choice was a rather ‘delicate’, yet extremely precise, tool grinding machine, the Kelch SZ34”. LACH DIAMANT® and the manufacturer from Southern Germany worked closely together in order to adapt the machine specifically to PCD grinding. After the production license was transferred, LACH DIAMANT® continued to build this machine under the new names “pcd-100” (equipped with swivel part) and “pcd-300” (equipped with optional adjustable spherical head).
Requests to produce PCD-tipped rotating tools such as milling cutters, scoring saws and saws were fulfilled at productronica in Munich in 1977.
LACH DIAMANT® had chosen GRP (glass fiber enforced plastic), an extremely hard-to-machine material for this “trial run of PCD-tipped rotating tools”. GRP is used as base material (PCB) in the production of circuit boards. 35 hours of grinding time for twelve teeth was accepted in the false hope that “we would eventually find something better”. Not at all. With the grinding technology of the time, there was no reduction possible. The initial enthusiasm of the exhibition visitors quickly gave way to accusations of withholding these cost-cutting miracle tools. Potential customers held this grudge for years.
Machining of composite materials
In 1978, one and a half years after this rocky start, a memory triggered another brilliant idea. Horst Lach remembered the words of his father that “electricity has a major part in grinding diamonds (he was talking about natural diamonds)”. Horst Lach was reading an advertisement for Fanuc erosion machines of the former company Matra.
“The reader should know that at the time GE and supplier DeBeers still used electro-plated diamond cutting wheels for cutting PCD blanks: the back of the hard metal surface of up to 6.4 mm round PCD blanks was first scored, then broken. At that time spark erosion had not yet been discovered”. His interest was piqued.
A visit to Matra would change the world of machining. After a first successful attempt to machine and form the electro-conductive PCD via spark erosion, this new process opened up the same possibilities for PCD which hard metals had finally established over HSS and ceramics. LACH DIAMANT® entered the market of machining wood and composite materials by founding LACH-SPEZIAL-WERKZEUGE GmbH which in turn established LACH DIAMOND® INC. for the American and Canadian markets.
A very bright future
PCD diamond tools proved to be 250-300 times as efficient as hard metaltipped woodworking tools. NC manufacturing technology was soon developed into CNC technology with multi-axis machines. “Today we know that this technology did not stop at metal machining. All the advancements of today’s automobile, aircraft, energy (especially wind energy with CFRP wings), sports and medical industries – to name only a few – would not have been possible without diamond, without polycrystalline synthetic cutting materials, including so-called mono diamonds and CVD (chemical vapour deposition)”.
After the development of spark erosion, or electrical discharge machining, Horst Lach obtained one of the first European patents. He withdrew the patent voluntarily after a Swedish tool manufacturer lodged an appeal. This discovery opened up a vision of a very bright future. Continuous innovations have proven this up to this day. LACH DIAMANT®’s entrepreneurial success with erosion technology is particularly evident in its technologically mature, well-engineered erosion grinder, Dia-2200-mini”, which machines diamond tools for the wood and plastics industry. With its extensive portfolio LACH DIAMANT® stands at the cutting edge of machining and grinding technology (Future for Today).
Horst Lach
