GERMANY 02Production Engineering as a Science

The industry association, specialist makers and high-speed steel (1890–1903)

VDW: makers join forces

On December 7, 1891, at the call of Ernst Schiess, a Düsseldorf maker of large machine tools, the heads of 11 companies met at the Hotel Kastens in Hannover and formed the machine tool makers' association VDW (Verein Deutscher Werkzeugmaschinenfabriken, the German Machine Tool Builders' Association). Its aim, as recorded by the association, was “to strengthen relations among the leading makers.” Schiess became its first chairman and served until his death in 1915^[2][3]. According to the NDB, as chairman Schiess was also involved in drawing up the state's new tariff schedule and preparing trade treaties^[24]. Makers acting together to deal with the state, later supporting research and running trade fairs: in Japan, the equivalent body is the Japan Machine Tool Builders' Association (JMTBA).

The VDW itself gives 1891 as its founding year, but the NDB entry on Schiess dates the VDW that united the makers to 1898^[24]. The difference probably reflects the year the organization was formally constituted, but we could not confirm this. Note that 1892 is the founding year of VDMA, the association of the whole machinery industry, which is easily confused with it^[2].

Specialist makers with their own strengths

In the 1890s, makers specializing in particular machine types grew up one after another. In 1890 Pittler of Leipzig brought out a machine with a turret (a tool holder that brings the tools into use in turn); in 1894 it increased the turret's holes from 6 to 16, and in 1895 it became a joint-stock company and a specialist maker of turret lathes^[5][7]. In 1892 Dingler's journal presented Pittler's precision lathe as a "universal metalworking machine," writing that it could be driven by treadle or by a belt from the overhead line shaft^[4]. In 1894 Hermann Heller founded his business in Nürtingen; it later made thread-cutting machines and circular saws, and from 1908 radial drilling machines^[6]. Wanderer, a Chemnitz bicycle maker, found that the milling machines it bought were not good enough, so in 1898 it began building its own, and in time it became a leading milling machine maker^[15]. In 1897 Hermann Pfauter of Chemnitz applied for a patent on a hobbing machine that could also cut helical gears (for details, see Chapter 8)^[12][13].

Rivalry with America also came into the open. In 1898 Deutsche Niles was set up in Berlin with capital from banks and the electrical company AEG, to build machines using the technology of the American Niles Tool Works. Its aim was to strengthen domestic machine tool production and push American products out of the market^[14].

Loewe's Moabit works: beyond the American model

In 1896 Loewe of Berlin transferred its arms division to a new arms company, DWM, and became a machine tool maker. At the new works it built in Moabit in 1896–98, it invited American engineers to introduce interchangeable production, and adopted group drive by electric motors (several machines driven together by a single motor), flow production of machine tools, short transport routes and a model measuring room. In 1901 it began licensed production of cylindrical grinders from Norton of the US, and in 1901–02 it set up Germany's first in-house standards department^[10]. Because the works also made steel balls and ball bearings, Loewe asked Richard Stribeck to study the strength of balls and races; this became the basis of ball bearing design^[10]. Before World War I, Loewe became the largest machine tool factory in Europe, according to the NDB^[10]. It was this works that Schlesinger joined in 1897.

1900: the shock of high-speed steel

At the 1900 Paris World's Fair, Taylor and White of the United States demonstrated cutting tools of high-speed steel (HSS), which kept cutting even at speeds that made the tool tip glow red. The lathe at the fair was an extremely rugged machine driven by a 40-horsepower electric motor^[16]. Loewe brought these tools back to Berlin and tested them on a lathe and a drilling machine at full capacity, and both machines broke down in less than a month^[17]. When the tools get better, it is the machine that gives way. A 1914 German technical encyclopedia sums up that progress in the lathe was driven by high-speed steel: more spindle speed steps, and every part built stronger^[33]. The American side of the high-speed steel story appears in the American Machine Tool Archive, Chapter 2.

What changed on the shop floor. High-speed steel cut several times faster than the carbon tool steel before it. Cutting fast and deep needs power to turn the spindle (horsepower), rigidity in the spindle and ways, and room for the chips to escape. Machines driven by thin belts from the overhead line shaft lacked the power, and through thicker belts, geared headstocks and eventually an electric motor for each machine, the very way machines were driven was rebuilt.

University laboratories and technical journals (1904–1913)

Schlesinger and the chair at TH Berlin

Georg Schlesinger (1874–1949) studied mechanical engineering at TH Berlin and joined Loewe in 1897. In 1899 he became head of jigs, tools and mass-production equipment, and in 1902 chief designer, introducing into the works a system of fits and tolerances he had devised himself. He wrote up the system in a dissertation on measurement in the factory and the making of interchangeable parts, earning his doctorate in 1903^[11]. In July 1904 he became professor of the newly created chair of "Machine Tools, Factory Equipment and Factory Management" at TH Berlin. It was the first chair of its kind in Germany and the origin of today's Institute for Machine Tools and Factory Management (IWF) at TU Berlin^[11][18][20]. Before taking up the post he made a several-week inspection trip to the United States for Loewe, and the following year he turned his report on the machine tools at the Liège World's Fair into a book^[18][19].

A company's chief designer becoming a university professor: this career shaped the character of Schlesinger's research. Its aim was to be genuinely useful in the factory.

The machine tool testing laboratory and Werkstattstechnik

In 1907 Schlesinger set up a machine tool testing laboratory (Versuchsfeld für Werkzeugmaschinen) at the university, the first in Germany. The university provided the building, the state paid the running costs, and makers donated or lent the machine tools used in the tests^[27][28][29]. In the same year, 1907, he founded the technical journal Werkstattstechnik ("workshop technology") with Springer and edited it for about 30 years. Its aim was to link university research and the shop floor^[11][18][30]. From 1912 the journal worked with the publisher of the American trade journal Machinery, and Schlesinger selected about 40% of its articles from Machinery. In 1911 it had about 2,200 subscribers^[18]. It was a system for bringing news of the latest American factories to German shops every month.

At the laboratory, machine tools were actually run and measured. Test reports appeared on a belt-driven lathe in 1912 and on a shaper driven by its own electric motor in 1921^[32][44]. The NDB judges that Schlesinger's research on tool steels, drills and milling cutters changed machine design toward machine tools able to withstand the large forces of cutting hard steel at high speed^[11].

The WZL in Aachen and translating Taylor

In 1906 the technical university in Aachen also gained a chair of machine tools, the second in Germany, and Adolf Wallichs, who had headed the mechanical department of a steelworks, became its professor. This year is regarded as the beginning of today's Laboratory for Machine Tools and Production Engineering, the WZL^[21][22]. Wallichs translated one book by the American Taylor after another. In 1908 he published On the Art of Cutting Metals as Über Dreharbeit und Werkzeugstähle ("Turning and tool steels"), writing in the preface that because the units of cutting speed (m/min or mm/s) were not standardized in Germany, he had unified them as m/min^[31][16]. In 1909 he also translated Shop Management^[18]. Today it is taken for granted on Japanese shop floors to write "cutting speed V = ○ m per minute," but research began with unifying that very unit. The WZL building in Aachen was delayed by the war and inflation, and was completed in June 1924 with donations from Rhineland and Ruhr industry^[21]. Wallichs's successor in 1936–37 was Herwart Opitz, who would lead the WZL after the war^[73].

Toward one motor per machine (individual drive)

Once machines that could cut hard and fast with high-speed steel were needed, the system of belting each machine from the overhead line shaft was replaced, despite the higher cost, by an electric motor for each machine (individual drive). The VDW's commemorative history gives the example of a 1910 Wanderer milling machine with a built-in motor^[2]. The 1906 encyclopedia includes a large Schiess vertical lathe driven by a motor of about 25 hp (up to 9.5 m in diameter, 20 table speeds)^[23], and the 1914 encyclopedia a Boehringer precision high-speed lathe with a motor mounted on the headstock and a 300-tonne Schiess vertical lathe with an 11 m faceplate^[33]. Boehringer itself says it built the first lathe driven by an electric motor in 1896^[9]. Building the motor into the machine made it easier to change speeds without shifting belts, and allowed machines to be placed anywhere. This was a precondition for rearranging factories in the order of operations, the later flow production.

In 1913, at the general meeting of the VDI (Association of German Engineers) in Leipzig, Schlesinger lectured on "Factory management and management science," discussing the strengths and weaknesses of Taylor's system^[29]. In the same year he proposed Germany's first standard for screw threads^[11].

World War I, standards and rationalization (1914–1923)

Schlesinger at the arms factory

When World War I broke out in August 1914, Schlesinger was put in charge of the rifle factory at the Spandau arsenal, aiming to raise output from 450 to 1,000 rifles a day. Within a few months of the outbreak, Loewe's works was also working at full capacity^[11][28]. Machine tool makers built machines for turning shells and boring machines for gun barrels, and Niles in Berlin also made the shells themselves^[9][14]. From 1915 he also worked with the surgeon Sauerbruch on artificial arms and legs for people who had lost limbs in the war^[11]. The Hindenburg Program of 1916 ordered a huge increase in arms production, and at the end of the year the weapons design offices were merged into one, advancing the standardization of parts^[28].

The beginnings of standards: NADI and DIN 1

Building hundreds of thousands of weapons required the dimensions of small parts such as screws, pins and keys to be the same in every factory. In May 1917, on the initiative of Hellmich and others at the Spandau artillery works, a "Standard Parts Committee for General Mechanical Engineering" was formed with the backing of the VDI. This was the forerunner of today's DIN (German Institute for Standardization)^[37][38]. On December 22 it became the "Standards Committee of German Industry (NADI)," and in March 1918 the first standard, DIN 1 "Taper pins," was issued^[39][43]. In 1926, as its work had extended beyond industry, it was renamed the "German Standards Committee (DNA)"^[39][37]. By the 1925 Leipzig fair there were already more than 800 standards, and fields such as screw threads, paper sizes and keys had been compiled into books. A transmission assembled from the parts of seven companies was displayed to show that, thanks to standards, any company's bearings and shafts were interchangeable^[52].

What it meant on the shop floor. The reason writing "M10," "A4" or "DIN 912" on a drawing is enough to specify a part is that standards exist. For machine tools too, once threads, fits, spindle noses and tool shanks are standardized, machines, tools and fixtures can be bought from different companies and combined. German standards were born from the wartime unification of parts, and their content was created by machine tool makers and university researchers (from 1930 the fits committee was led by Kienzle, a graduate of TH Berlin^[45]). Today's thinking on fits is explained on the Fits page.

From Taylor to the rationalization movement

In 1915, in an obituary for Taylor, who had died in March, Dingler's journal wrote that few new teachings had stirred engineers and economists as much as "Taylorism"^[36]. Postwar Germany made this idea a national movement. In February 1918 the Committee for Economical Production (AWF) was formed within the VDI^[29][42], and in May, on the VDW's initiative, a research society was set up to fund the machine tool testing laboratory, with Schlesinger as chairman and the VDW running its office^[29]. In October, on Schlesinger's initiative, a group for "industrial psychotechnics" under the psychologist Moede was set up at the laboratory, starting research on measuring workers' aptitude^[29]. In June 1921, on the initiative of the Reich Ministry of Economics, the RKW (Reich Board for Economic Efficiency), the headquarters of the efficiency movement, was set up in Berlin; under its chairman Carl Friedrich von Siemens it took Taylor and Ford as its models^[46][47]. In 1924 REFA, which set standard times by timing work, was also founded^[42]. Research shows, however, that Ford-style flow production took root in Berlin's engineering industry only in the 1930s; in the 1920s, rationalization in machine tool shops mainly meant time study and standardization^[46].

Leipzig's technical fair and INDEX

In 1918 a company for a technical fair (Technische Messe) was founded in Leipzig, and from 1920 the fair was held on today's Alte Messe grounds^[41][8]. At the fifth fair in spring 1923, in the middle of the inflation, about 270 machine tool makers exhibited. Dingler's journal wrote that no world's fair had ever seen one country put on such a complete display, and urged foremen and charge hands above all to come to the fair to see the machines running and learn from them^[50]. In 1925 the VDW's huge new Hall 9 was built^[52]. A 1936 trade journal wrote that the machine tool exhibit was like a "large factory" in which machines actually turned, milled, planed and drilled, and recalled that before World War I production machinery had not been considered something to sell at a fair^[78]. The fair had become a place to buy machine tools by "seeing, running and comparing" them.

In 1914, the year the war began, Hermann Hahn founded the automatic lathe maker INDEX in Esslingen^[35]. The name is said to come from indexing the turret.

Carbide tools, accuracy testing and the road to the Depression (1924–1933)

Widia: a tool like diamond

In March 1923 Karl Schröter of the light bulb maker Osram applied for a patent on a "sintered hard alloy," made by pressing tungsten carbide powder with a little cobalt or a similar metal and firing it (DE 420689, published October 1925). The US patent for the same invention was granted in August 1925 and came to be owned by GE^[51][77]. Krupp acquired the rights and applied for the trademark "Widia" in December 1925 (registered May 1926)^[53][54], launched it as a carbide tool in 1926 and showed it to the public at the Leipzig spring fair of 1927^[55][54]. The name comes from "wie Diamant" (like diamond).

According to Sumitomo Electric's technical journal, where high-speed steel cut steel at 20–40 m per minute, carbide tools reached about 100–150 m, roughly four times as fast^[56]. What had happened with high-speed steel in 1900 happened again on a larger scale. Machine tools now needed faster spindles, greater rigidity, and less vibration so that carbide edges would not chip. The first carbides were best at cutting cast iron and nonferrous metals; carbides that cut steel well spread in the 1930s^[56]. How to choose carbide tools today is explained on the Machining page.

1927: the accuracy testing book

The German achievement of this era most directly connected to today's factories is Schlesinger's book on testing the accuracy of machine tools. Published by Springer in 1927, Die Arbeitsgenauigkeit der Werkzeugmaschinen ("The working accuracy of machine tools") set out in tables, for each type of machine such as lathes, milling machines and drilling machines, what to measure and how (test items and methods) and how much error to allow (tolerances). Later editions were called Prüfbuch für Werkzeugmaschinen ("Test book for machine tools")^[11][57][58]. In 1932 an English edition, Inspection Tests on Machine Tools, appeared in London (titled Testing Machine Tools from the second edition) and spread worldwide^[62].

Shigeru Ueno, an expert on machine tool standards, writes that this "Schlesinger standard" and the 1933 cutting test method of the Frenchman Salmon are the two sources of today's machine tool test standards, and that their developed form is today's ISO standard (ISO 230)^[49][75]. Measuring spindle runout, table straightness and the squareness of spindle to table with dial gauges and precision levels: much of the procedure used today when a machine tool is installed or its accuracy checked took shape here. The NDB judges that with this book Schlesinger showed the importance of being able to make parts precisely and interchangeably to standard^[11].

The VDF, Soviet orders and the Depression

In the late 1920s, makers also began to join forces. In 1928 four lathe makers (Boehringer, Franz Braun, Heidenreich & Harbeck and H. Wohlenberg) formed the "VDF (Vereinigte Drehbank-Fabriken)," dividing up the lathes each would make by size and selling them jointly^[9][59]. In 1929 Loewe merged with the electrical company Gesfürel^[10]. During the Great Depression, orders from the Soviet Union kept companies going: more than half of the VDF's exports went to the USSR, and Gildemeister too kept producing thanks to Soviet orders^[9][61]. Schlesinger visited the Soviet Union in 1925 and 1929, and the orders placed there are said to have kept German machine tool makers busy until the end of the 1930s^[11]. Economic historians have shown from patent statistics that in the late 19th century and the 1920s, German machine tool makers pursued a strategy of catching up by imitating American technology^[64]. While trying to overtake America through research and standards, they also kept learning from it.

1933

In 1933, under the Nazi regime, Schlesinger, who was Jewish, was driven from the university and, suspected of treason because of his Soviet connections, held in custody for about nine months. The VDW, with which he had long worked, acted to secure his release. In 1934 he was expelled from the country; after Zurich and Brussels he moved to Britain in 1939, and he died near London in 1949^[11][28]. His chair at TH Berlin passed to Kienzle in 1934^[45]. The era in which machine tool building was drawn into rearmament and state control continues in Chapter 3, “War and the East–West Division”.

⛩Links with Japan

Hobbing machines and lathes: German machines as models

The first hobbing machine to reach Japan is said to have been one by Pfauter of Germany, imported around 1906^[25][26]. Some Japanese hobbing machines of the Taisho era were modeled on Pfauter's, and domestic production of gear cutting machines began from German machines (Japanese Archive, gear cutting machines chapter). For lathes, from 1935 to 1956 Ikegai built engine lathes with their parts grouped into units, modeled on the German VDF lathe. One built in 1937 survives at the Nippon Institute of Technology Museum of Industrial Technology^[74] (Japanese Archive, Chapter 1). The VDF is the 1928 association of lathe makers described in this chapter.

Accuracy testing and standards

The history of accuracy testing of machine tools in Japan is said to begin with the first machine tool exhibition, held by the Ministry of Agriculture and Commerce in October 1921, where the accuracy of the exhibited machines was tested^[48][49]. In April of the same year, 1921, the Industrial Standards Investigation Committee was formed, and work began on the Japanese Engineering Standards (JES)^[76]. In 1933 the committee compiled a report on German standardization, and in 1937 the Journal of the Japan Society of Mechanical Engineers carried "Machine tool standards in Germany"^[65][66]. Schlesinger's accuracy testing book was translated in 1939 as Kosaku kikai no kensaho (Inspection methods for machine tools)^[67]. Ueno writes that there can be little dispute that the Schlesinger standard had the greatest influence on machine tool testing in Japan, and explains that today's JIS B 6191 is a Japanese translation of ISO 230-1^[75]. A German book of 1927 is thus connected, through ISO, to Japan's present machine tool inspection standards. Schlesinger's articles on rationalization were also translated in 1932 as Bedo-shiki seisan kanri (Bedaux-style production management)^[63].

cemented carbide tools

Japan was quick to follow with carbide tools too. Shibaura Engineering Works succeeded in developing cemented carbide in August 1929 and launched it as "Tungaloy" in 1930^[60]. Sumitomo Electric Wire & Cable Works made trial carbide wire-drawing dies in 1928 and began making carbide tools in 1931^[56]. Sumitomo's technical journal presents Osram's invention (1923), Krupp's Widia and its own development as one continuous story^[56]. However, we have found no record that a Japanese company brought in Widia's technology directly.

FAQ

What did Georg Schlesinger do?

He went from chief designer at Loewe in Berlin to professor, in 1904, of Germany's first chair of machine tools and factory management, at TH Berlin. In 1907 he founded the machine tool testing laboratory and the technical journal Werkstattstechnik, and he advanced standards for fits and screw threads, research on cutting and machine tools, and research on workers' aptitude. His 1927 book on the accuracy testing of machine tools is regarded as the source of the testing standards that led to today's ISO 230.

Did machine tool accuracy testing (ISO 230, JIS B 6191) come from Germany?

Germany is one of its sources. Schlesinger's 1927 book set out, for each type of machine, the test items, the methods and the permissible errors; it was translated into English in 1932 and into Japanese in 1939. An expert on machine tool standards writes that this book and the 1933 cutting test method of the Frenchman Salmon are the two sources of today's test standards, and that the Schlesinger standard had the greatest influence in Japan. Today's JIS B 6191 is a Japanese translation of ISO 230-1.

Was the carbide tool born in Germany?

Yes. Cemented carbide, made by adding cobalt or a similar metal to tungsten carbide powder and sintering it, was patented by Karl Schröter of Osram in 1923, and Krupp launched it as a tool under the name "Widia" in 1926 (shown to the public at the Leipzig spring fair of 1927). In Japan, Shibaura Engineering Works brought out "Tungaloy" in 1930, and Sumitomo brought out carbide tools in 1931.

When and why were DIN standards created?

In 1917, during World War I. To mass-produce weapons, the dimensions of parts such as screws and pins had to be the same in every factory, so a standard parts committee was formed in May and the Standards Committee of German Industry (NADI) in December. The first standard, DIN 1 "Taper pins," was issued in March 1918.