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Japanese cutting tool makers, and why they make a difference on the shop floor

The author works with tools from everywhere, and the Japanese ones are those he goes back to most gladly: clear catalogues, tolerances that hold, few surprises from one batch to the next. This is not a ranking: it is a map of who they are, where they come from and what they are good at.

9 min read

What they have in common

Almost all of them have a long history in cemented carbide or in one precise speciality, often going back nearly a century. Many make the material, the coating and the finished tool in house. And almost all publish very careful technical catalogues, with identification tables that are a reference even for users of other brands: Mitsubishi Materials' ISO insert table, for one, is among the clearest around.

The other thing they share is specialisation: some cover everything, others do one thing only, and do it thoroughly.

Mitsubishi Materials

The group was born in 1871 in mining; since 1931 it has sold cemented carbide tools under the name Tridia, and since 1942 it has made cutting tools on an industrial scale. From 2017 its tools carried the DIAEDGE brand; since April 2025 the brand is simply Mitsubishi Materials again. It has owned 100% of MOLDINO since 2020.

Strength: a complete range for turning, milling and drilling, with technical documentation that is a school in itself. The mining roots still show in its rock and construction tools.

Sumitomo Electric Hardmetal

Sumitomo Electric began in 1897 as a copper rolling mill. Carbide came from wire drawing: carbide dies from 1928, cutting tools under the IGETALLOY brand from 1931. The 1950s and '60s brought indexable inserts, ceramics and titanium-carbide cermet; the late '70s its own superhard materials: SUMIBORON (CBN, 1977) and SUMIDIA (polycrystalline diamond, 1978).

Strength: superhard materials. Anyone turning hardened steel or non-ferrous alloys with CBN and PCD meets their grades sooner or later.

Kyocera

Founded in Kyoto in 1959 as Kyoto Ceramic, it entered cutting tools in 1971, starting from ceramics for high-speed machining. The rest it built partly through acquisitions: Tycom (circuit board drills, USA, 2001), Unimerco (Denmark, 2011, now its European cutting tool headquarters) and SGS Tool (solid end mills, USA, 2016).

Strength: cermet and ceramics, born from its history in technical ceramics. The company presents its CCN grade as the first CVD-coated cermet.

Tungaloy

This is where Japanese cemented carbide was born: in 1929 Shibaura developed Japan's first cemented carbide and named it Tungaloy, from tungsten + alloy. For decades it was Toshiba Tungaloy; in 2004 it left the Toshiba group and in 2008 joined IMC, the Iscar group. It is based in Iwaki, Fukushima. It has announced a merger with NTK Cutting Tools from 1 January 2027, keeping the Tungaloy name.

Strength: a wide indexable range: turning, parting and grooving, milling and drilling.

MOLDINO

Born in Osaka in 1928 as Teikoku Cutter Works, a milling cutter maker. It later became Japan Tool Works, moved into the Hitachi orbit and in 1987 took the name Hitachi Tool Engineering. It has been in the Mitsubishi Materials group since 2015, has used the MOLDINO brand since 2017 and has been called MOLDINO Tool Engineering since 2020.

Strength: dies and moulds. It is one of the few makers that states it designs everything for a single sector, from material to inspection: solid and indexable cutters, drills, threading and chamfering tools, all made for mould work.

OSG

Founded in Tokyo in 1938 by Hideo Osawa to make taps and dies, based in Toyokawa (Aichi) since 1964. From taps it moved to gauges, thread rolling dies, end mills (HSS in 1970, carbide in 1980) and drills (1984). Taps are still its largest sales item, and the "A Brand" is its premium line.

Strength: threading in every form: cutting and forming taps, thread mills, gauges. Its tap drill tables are among the references we check this site's tap drill pages against.

Yamawa

Founded in Tokyo in 1923, it is the oldest maker on this list and does one thing only: threading tools, plus centre drills. After the war it took part in drafting the JIS standards for taps; all its products have been JIS certified since 1955. Production is in Japan, in Yamagata and Fukushima, and in Europe it has long worked with an Italian distributor.

Strength: taps, cutting and forming, split by material with rare precision. Its forming tap drill tables also appear on our pages, side by side with OSG's.

NS Tool

Born in Tokyo in 1954 as Nisshin Kogu Seisakusho, at first a machine builder, it became NS Tool in 1991. It specialises in small-diameter solid carbide end mills and concentrates development and production at its Sendai plant. The company states it lists a 0.01 mm diameter end mill as a standard product.

Strength: micro end mills for moulds, electrodes and precision parts.

Union Tool

Founded in 1960, it built its strength on printed circuit board drills, where demand today is for diameters below 0.3 mm. From there it moved to solid carbide end mills (UNIMAX series from 1986) and diamond-coated end mills (2012). The company states micro drills down to 0.02 mm, with the diameter guaranteed even below 0.05 mm.

Strength: micro drilling and small, rigid end mills, measured with instruments developed in house.

Sources

Dates and facts come from the makers' official pages. Statements such as "the smallest" or "the first" are the companies' own claims. Toolhelix has no commercial relationship with any of these makers; trademarks belong to their owners.

Read the code of any insert, from any brand.

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