ITALY 06The Lineage of Italian Grinding Machines

Imported grinders and car factories (1909–1920s)

Grinding machines began to appear in Italian factories thanks to the car. In May 1909 Godfrey Carden, an agent of the US Department of Commerce and Labor, visited the Torino car company Itala (about 800 workers) on a trip to find out how far American machine tools were used in European factories. The works had nine grinders by Landis of Waynesboro in the US (No.1, No.1½, No.3, No.23), Brown & Sharpe universal, No.13 and surface grinders, and a cylinder grinder by Mayer & Schmidt of Germany^[1]. Landis was known for grinders that traverse the wheelhead along the work to grind long, heavy shafts, and it supported American car factories in grinding crankshafts and camshafts (the chapter on American grinding machines).

What stands out in the same report is that among the machines Itala built itself was “a universal grinder for grinding ball bearings”^[1]. Ball bearings will not turn without hardened balls and rings that are truly round and uniform in size. A factory that could not buy bearings from outside, or wanted to make its own, had no choice but to build the grinding machines itself. This is an early documented example of an Italian grinding machine. Meanwhile, the army's precision works in Rome, the Laboratorio di Precisione (about 150 workers, making rangefinders and gun sights), had only a few American machines, one of them a Landis grinder. Most were German, and Carden recorded the works' complaint that “American makers have never once come to call”^[1].

Lancia's grinders: from 4 to 23

Duccio Bigazzi and colleagues, who studied the machine registers of Lancia in Torino, give figures for the change from 1907 to 1914. Grinders rose from 4 to 23 and gear cutters from 2 to 17, and the grinders, gear cutters, planers and shapers it bought were all American-made^[2]. Production grinding began by 1911 at the latest, and the 1914 inventory lists Brown & Sharpe precision grinders, Norton heavy grinders for grinding crankshafts, and Heald planetary internal grinders for grinding cylinder bores. The Norton grinder cut a crankshaft job that had taken five hours of turning, filing and polishing to 15 minutes^[2].

What changed in this era. Grinding changed from “polishing after the lathe has brought the part to size” to the work of “grinding to final size after hardening.” Two methods, plunge grinding (Norton), which grinds in one go with a heavy, rigid machine and a wide wheel, and planetary internal grinding (Heald), in which the work stays still and the wheel spindle travels around in a circle, set the pattern for how car engine parts were made. Italian factories bought these new American machines soon after they came onto the market in the US^[2].

Domestic grinders and grinding wheels: the age of self-sufficiency (1914–1945)

After the First World War, many small precision engineering shops sprang up in Italy. Many of the companies that later became specialist grinder makers started out in subcontract machining and machine repair. Morara of Bologna began in 1914 as a shop for subcontract precision machining and machine tool repair^[3]. In Luino, near Lago Maggiore, Giuseppe Ghiringhelli and Mario Pisoni set up a subcontract turning shop in 1921, and moved into grinding work from 1930^[4]. In Acqui, Piemonte, the Tacchella brothers' company appears in the trade directory of a 1934 railway journal as a firm doing pumps, cranes, ironwork and repairs, and electric motor repair^[8].

Books spreading grinding know-how also appeared. In 1926 the Milano publisher Hoepli brought out, in its series of technical manuals, Amerigo Giordano's Abrasivi, affilatrici, rettificatrici (abrasives, tool grinders and grinding machines), a small 403-page book covering description, selection and use^[5].

Aircraft orders and the first domestic grinders

In the 1930s Italy was strengthening self-sufficiency (autarky), freeing itself from reliance on imports (for the trend of the era, see Chapter 1, “From Imports to Domestic Production”). Domestic grinding machines began within this. In 1934, prompted by a large order from the aircraft industry, Morara began designing and building internal and external grinders, which were then almost unobtainable on the Italian market^[3]. The bearing bores and cylinders of aero engines were exactly the parts Lancia had been grinding on American machines. In Torino, Riccardo Favretto started a parts machining shop in 1934, machining brass and special alloy parts for ships and aircraft^[7].

In 1935 Ghiringhelli of Luino built a centerless grinder for use in its own shop, to its own design^[4]. In centerless grinding the work, held neither on centers nor in a chuck, sits between a fast-turning grinding wheel and a slowly counter-rotating regulating wheel, and supported from below by a blade (work rest), it is ground. The regulating wheel acts as a brake that sets the speed of the work, and the speed difference does the cutting. Tilting the regulating wheel slightly makes the work feed itself along its axis, so pins and shafts can be passed through and ground one after another (through-feed). It is a way of grinding that needs no center holes and suits mass production. This method, which became practical in the US in the 1910s–20s (the chapter on American grinding machines), was built by a Luino subcontract shop for its own work, and that was the starting point of a later specialist maker. Around the same year, 1935, Tacchella's repair shop in Acqui also turned to building machine tools, and by 1942 it had more than 100 workers^[9]. In 1937 the three Novarese brothers started Meccanica Nova near Bologna, and in 1939 they built their first internal grinder under the name NOVA^[10].

Grinding wheels and artificial abrasives: plants under license

A grinder is useless without a grinding wheel. The main materials of wheels are grains of artificial corundum (alumina) and silicon carbide, made in electric furnaces (for how they are made, see the chapter on American grinding machines, “A revolution in wheels”). In Italy a 1932 law allowed artificial corundum and silicon carbide powder for making grinding wheels to be brought in under temporary importation (a scheme for bringing goods in duty-free to be made into products), and this arrangement was renewed in 1936. Artificial corundum was capped at 1,000 quintals (100 t) for the two uses combined^[6].

In Italy at the time, building or enlarging a factory required government permission, and the official gazette records permits for grinding wheel plants. In 1937 Silvio Morando & C. of Ronco Scrivia was allowed to enlarge its plant for silicon carbide and artificial corundum refractories and grinding wheels^[11]. In March 1940 I.M.A. (Industria Mole Abrasive) of Rome was granted a grinding wheel plant, while a Torino grinding wheel plant applied for by Amerigo Giordano, author of the 1926 manual, and others was not approved^[12]. Even people with grinding know-how who wanted to make wheels lived in an era when the state decided how many plants there would be.

What it means on the shop floor. That many Italian grinder makers began as “a subcontract shop that built grinders for its own work” still shows in their products today: they concentrate on one type (only centerless, only internal, only surface) and adapt the specification to the customer's parts. When looking for a used machine, knowing what the maker has specialized in makes it easier to choose whom to ask about parts and service.

Recovery, imports and specialist makers (1945–1974)

At the end of the war, machines in northern Italian factories were carried off by the German army or destroyed by bombing. After the war the official gazette printed, in several installments, lists of machines recovered from Germany and Austria, asking their owners to claim them. The 14th list, of March 1950, includes a grinder (serial no. MM 152) of C. Morara & C. of Bologna^[14]. It is evidence that prewar domestic grinders were actually in use in factories. Right after the war Favretto made a business of repairing and rebuilding bomb-damaged machine tools, and in 1950 it started production of the surface grinder for which it became known^[7]. Ghiringhelli and Meccanica Nova exported their first grinders in 1948^[4][10]. At Tacchella, founder Andrea Tacchella died in 1948, and his two young sons took over the company^[9].

Marshall Plan grinders: measuring automatically and stopping

Large car makers bought new machines with American loans. Between February 1948 and February 1950 Lancia received three IMI-Eximbank loans ($2.32 million) and an ERP (Marshall Plan) loan ($0.8 million), and among the machines worth about $1.2 million that it ordered from the US were 19 grinders (mainly Landis and Cincinnati)^[2]. A further application of January 1951 (not realized, as the aid did not continue) listed two Heald internal grinders for gear bores and 14 Landis external grinders for shafts and shoulders, both described as machines that measure automatically and stop when the size is reached. The reason given was that they were “highly accurate and productive, and usable by unskilled workers.” Micromatic cylinder honing machines and Gisholt superfinishing machines were also included^[2].

This “measure while grinding” technology produced a world-class company in Italy too. In 1952 the engineer Mario Possati founded Marposs in Bentivoglio near Bologna, to make electronic measuring and control instruments^[15]. An in-process gauge, fitted to the grinder to measure the work during grinding and retract the wheel at the target size, spares the operator from stopping again and again to measure with a micrometer. It is standard equipment on today's grinders.

Artificial abrasive plants, and special machines that had to be imported

According to a 1951 survey of world abrasives compiled by the US CIA, Italy's artificial abrasives were made by Fratelli Galtarossa of Verona at plants in Domodossola in the Alps and in Trento, with capacities of 8,000 t of alumina and 840 t of silicon carbide; 1949 production was 4,800 t of alumina and 500 t of silicon carbide. About ten grinding wheel companies were listed, including the Corsico (near Milano) plant of the American firm Norton, Ermoli of Mainate and Bottaccini of Padova^[13]. Electric furnaces use huge amounts of electricity, so the plants were placed in mountain towns with hydroelectric power.

Special-purpose grinders, on the other hand, still had to be imported. In June 1957 the Italian government added to its list of items made easier to import from the dollar area (the US and others): gear grinders and coordinate (jig) grinders, long thread grinders, grinders for helical splines and involute shafts, jet engine blade grinders, and special machines that grind crankshafts with several wheels at once^[16]. A British trade journal wrote in 1960 that the Italian machine tool industry had grown fast after the war, but imported heavily the types of machine whose home market was small, while domestic makers concentrated on simple machines for Asia and Africa. Imports in 1958 were 15,200 t and £13 million^[18].

The specialist makers' machines: centerless, tool grinding, surface

Meanwhile, the specialist grinder makers refined their machines. Torino's Giustina showed rolling bearings and grinders for engine valves at the 1957 Torino Motor Show^[17], and in 1961 brought out the R90/C centerless grinder. Its grinding wheel, 20 inches (about 510 mm) in diameter and 10 inches wide, was driven at 16 hp, and the regulating wheel's speed could be varied steplessly from 12 to 72 rpm by a DC motor and a magnetic amplifier. Both wheels had hydraulic diamond dressers (devices that true the wheel's shape); wheel wear was compensated automatically, dressing ran automatically after a set number of parts or a set time, and an automatic in-process gauge could be fitted. The company also built double-disc grinders under license from Besly-Welles of the US^[20]. Such equipment turned centerless grinding from “a machine a master grinds by eye” into “a machine where you put the part in and it comes out at the set size.”

In 1961 Ghiringhelli built a new plant at Voldomino in Luino and moved there, and it appears as a centerless grinder maker in a British trade journal's listing. In 1965 it gave up subcontract work, and the company came to make nothing but centerless grinders from then on^[4][19]. Meccanica Nova obtained a license for external grinders from Van Norman of the US in 1967, and began making external as well as internal grinders^[10].

Tacchella of Acqui and Cassine grew with the tool grinder (affilatrici), which resharpens cutting tools, and the precision grinder. A 1968 newspaper feature reported 2 plants and 270 workers, exporting more than half of output, with customers including Fiat, Citroën and Rolls-Royce and destinations including the Soviet Union, Poland, South Africa and China. It offered about 400 kinds of accessories, and all its feed screws were finished by grinding. Manufacturers in the US, West Germany and Yugoslavia sought licenses to build its machines, and a new 10,000 m² plant went up at Cassine^[9]. Tool grinders resharpen the edges of end mills, drills and broaches to the correct angles; every factory needs at least one, so they were an easy product to export.

What it means on the shop floor. Automatic in-process gauges, hydraulic dressers, automatic wheel-wear compensation and stepless regulating wheel drives came into Italian grinders too in the 1950s and '60s. The settings on today's centerless grinders, “dressing interval,” “compensation amount,” and “regulating wheel tilt angle and speed,” are legacies of the devices of this era. For how to think about grinding conditions, see Grinding Basics: "Grinding conditions".

★CNC and the specialist makers today (1975–)

The 1970s were also a time of labor struggle. In March 1975, at Tacchella's Cassine plant with about 250 workers, the workers occupied the factory over promises of employment^[23]. In the same year Ghiringhelli showed a CNC centerless grinder at the EMO in Paris. The company says it was one of the very first makers to bring out a CNC centerless grinder^[4]. In a CNC centerless grinder, the feed (infeed) of the regulating wheel and the dresser movements that shape the grinding and regulating wheels are driven numerically. Stepped shafts and tapered parts could be ground without making templates (cams), and changeover times became shorter.

In 1980 Meccanica Nova built an internal grinder carrying a CNC developed in-house (the company says it was the first in Europe), and in 1993 it bought Famir International, a Torino grinder maker. In 2007 it brought out a multi-process grinder for the automotive industry, and today it concentrates on grinding bearing rolling elements and constant-velocity joint cages^[10]. In 1980 Morara built an 18,000 m² plant in Bologna, and by 2001 it had built more than 5,000 grinders. Its CNC grinders, which grind the bore and outside diameter simultaneously in one clamping, make concentricity easy to achieve because both are ground on the same axis^[3]. The company's 2001 description characterized its market as “strong competition with the large groups of Japan, Germany and Switzerland”^[3].

Machine bases, linear motors and digital twins

The machines' structure changed too. Ghiringhelli became a joint-stock company in 1981, brought out the APG centerless grinder for volume production in 2008, and in 2013 changed the machine base from cast iron to artificial stone (synthetic quartz). The company says this was to reduce environmental impact, but a stone base also absorbs vibration well and changes shape little with heat. In 2019 it showed at EMO Hannover the APG-DT centerless grinder, which carries Siemens's SINUMERIK ONE and can create a virtual double of the machine on a computer (a digital twin) to test machining in advance^[4]. The Morara and Tacchella brands live on under the IMT name, and a 2014 trade journal article shows the MTL 1000 external grinder with linear motors at work in a Bologna parts machining company^[26]. In April 2017 the three brands Morara, Tacchella and Meccanodora passed to Grinding Technology of Taiwan's Fair Friend Group (FFG)^[28][29].

In 2017 Favretto, the Torino surface grinder maker, joined the group of Rosa Ermando of Rescaldina (province of Milano; founded by Ermando Rosa in 1964)^[21][22], and now builds surface and profile grinders at the Rescaldina plant^[27]. Samputensili, the gear cutting tool maker, began building gear grinders in 1988^[24], and in 2010 it gave up hobbing machines to concentrate on tools and gear grinders^[25]. Its machine business passed to Germany's EMAG in 2021 and is now EMAG SU^[30] (the chapter on Italian gear machines). Ghiringhelli celebrated its 100th anniversary in 2021^[4].

What it means on the shop floor. Italian grinders have been chosen by the names of specialist makers: “for centerless, Ghiringhelli; for internal, Meccanica Nova or Morara; for surface, Favretto or Rosa; for tool grinding, Tacchella.” When looking for parts or service for an old machine, knowing which group a brand has moved to (Morara and Tacchella → IMT, Favretto → Rosa Ermando, Samputensili's machines → EMAG SU) tells you whom to contact.

Links with Japan

Japanese and Italian grinders both began with American grinders as their model. In Japan too, machines modeled on Norton tool grinders and Heald internal grinders from the US were built in the early Taisho era (the 1910s), and in wartime hydraulic universal grinders modeled on Landis were mass-produced (Japanese Archive, Chapter 3, "The Lineage of Grinding Machines"). The machines in Itala's works in 1909 and Lancia's in 1914 were the same Landis, Norton and Heald machines^[1][2].

After the war, Italy and Japan were linked through grinding measurement. Marposs of Bologna entered Japan in 1970, putting its first office in Tokyo and its next in a city with many car makers, selling directly rather than through agents and providing maintenance in Japan. In 1998 it earned 13% of its sales in Japan^[15]. The fully automatic grinders with in-process gauging and the CBN grinders that Japanese grinder makers developed in the 1970s (Japanese Archive, Chapter 3 "CBN and high-speed grinding" event) became strong competitors for the Italian specialists, and in 2001 Morara described its market as “competition with the large groups of Japan, Germany and Switzerland”^[3].

FAQ

Who first built grinding machines in Italy?

The earliest documented example is the universal grinder for ball bearings that the Torino car company Itala had built for itself by 1909 (from a US Department of Commerce and Labor inspection report). Among companies building grinders for sale, Morara of Bologna began making internal and external grinders in 1934, prompted by an order from the aircraft industry, and Ghiringhelli of Luino built its first centerless grinder in 1935.

Who makes centerless grinders in Italy?

The leading example is Rettificatrici Ghiringhelli of Luino (province of Varese). It began in 1921 as a subcontract turning shop, built a centerless grinder for its own use in 1935, and has made only centerless grinders since 1965. It showed a CNC centerless grinder at EMO in 1975 and celebrated its 100th anniversary in 2021. In 1961 Torino's Giustina also brought out the R90/C centerless grinder.

What kind of company is Marposs?

A maker of electronic measuring and control instruments, founded in 1952 by the engineer Mario Possati in Bentivoglio near Bologna. It is widely known for in-process gauges, fitted to grinders to measure size during grinding and retract the wheel at the target size. It entered Japan in 1970.

What has become of Morara and Tacchella?

In a 2014 trade journal article, Morara and Tacchella grinders are treated as IMT brands. In April 2017 Taiwan's Fair Friend Group (FFG) bought both brands, together with Meccanodora, from IMT through its affiliate Grinding Technology. For parts and service for used machines, look for the current contact by brand name.