Company history

The company’s line runs back to Tokyo Koku Kikai, set up in 1939 as a subsidiary of the utility Nippon Denryoku and turned during the war into a captive supplier of cutting tools to the Toyokawa Naval Arsenal. On that base, in March 1949, Tokyo Seimitsu Kogu — Tokyo Precision Tools — was incorporated with capital of $4,444 (¥2m), making cutting tools, precision parts and jigs for sewing-machine work. Occupation-era Japan was rebuilding its textile and machinery industries at the same time, and that gave a small tooling shop steady demand at the edges of both.

A cutting-tool maker is judged on the dimensions it produces, yet the instruments that verify those dimensions had to be bought from someone else. Tokyo Seimitsu began closing that gap sideways: mining bits in 1950, then mechanical-gauge instruments in 1951. In January 1953 it became the first company in Japan to industrialize a high-pressure flow-type air micrometer, a non-contact way of reading micron differences that until then had lived in academic laboratories. Customers in automobiles, electrical machinery and precision instruments — anyone managing tolerances in microns — followed.

The electrical version came next: in October 1957 the company put Japan’s first differential-transformer electric micrometer into volume production. Recognition and capacity arrived together — an Akashi Memorial Prize from the Japan Society for Precision Engineering in 1959 for work on automatic sizing devices, a temperature- and humidity-controlled wing at the Mitaka plant in 1960, and exports to the United States through Techni-Rite from 1961. A company that ground metal had become a company that measured it.

In April 1962 the two characters for “tools” were dropped from the name, leaving Tokyo Seimitsu; in August the shares were listed on the second section of the Tokyo Stock Exchange, thirteen years after founding. The renaming was less a declaration than an accounting: the product that had been an inspection aid had quietly overtaken the product it was meant to inspect.

Production then split in two and stayed that way for twenty years. The Hachioji plant, in western Tokyo, was completed in stages in 1963 and 1967 and gained a main building in 1971; the Tsuchiura plant, in Ibaraki, opened in 1969. Hachioji took general-purpose measuring instruments, Tsuchiura took coordinate measuring machines — CMMs, which trace a part’s surface with a probe and turn a three-dimensional shape into numbers, used to inspect engine components, aerospace parts and dies. A dedicated CMM plant followed at Tsuchiura in 1981. Mitutoyo had got there first domestically, so Tokyo Seimitsu competed on machine architecture and on software, spinning the software work out as Tosei Systems in 1985.

The market rewarded it: first-section status on the Tokyo Stock Exchange came in September 1986, twenty-four years after the initial listing, as CMMs began contributing seriously to earnings. Then, in a single year, the company went abroad on both flanks — TOKYO SEIMITSU EUROPE GmbH in West Germany in March 1989, TOKYO SEIMITSU AMERICA INC. in October. Selling direct to the quality-control departments of foreign carmakers and electronics firms also answered the tariff pressure of the trade-friction years.

The domestic instrument market was maturing, and the obvious extension — measuring and inspecting the silicon wafer itself — ran into a semiconductor-equipment market already carved up by Tokyo Electron and Advantest. Catching up by in-house development was implausible. So in October 1992 Tokyo Seimitsu bought SILICON TECHNOLOGY CORPORATION of the United States and took wafer-processing technology and a North American customer base in one movement. Forty-three years after founding, the company had a second business.

What followed was the unglamorous work of making an acquisition operable. TSK AMERICA INC. was set up in 1995 to hold the US subsidiaries together, and in 1998 four of them were merged into it. In 1999 the subsidiary Micro Technology was recapitalized to build wafer appearance-inspection systems, adding inspection to the processing line acquired with STC; it was absorbed into the parent in 2007. Plants went up almost continuously — Hachioji No. 2 in 1997, a new Hachioji main building in 2001, Hachioji No. 3 and a new Tsuchiura main building in 2005, a Tsuchiura semiconductor plant and CMM building in 2008 — because both businesses were now expanding at once.

Two governance moves bracket the decade. In June 2001 the service subsidiary Tosei Engineering was floated on the TSE second section, giving the group a parent-and-child listing; in October 2005 it was bought back in full by share exchange and delisted, ending the arrangement after four years as investors grew less tolerant of the conflicts of interest it created. Meanwhile the overseas map filled out — Shanghai in 2002 as Chinese fabs began to appear, Korea reorganized as ACCRETECH KOREA in 2007 to serve Samsung and SK Hynix. ACCRETECH — from “accurate” and “technology” — had by then become the group’s single overseas brand.

In June 2010 the registered head office moved from Mitaka to Hachioji, where the plants had been since 1963 — the paperwork catching up with the substance, as it had in 1962. A fifth Hachioji plant followed in 2011 and a sixth in 2016, and in 2012 the US branch opened three years earlier was converted into a proper subsidiary, ACCRETECH AMERICA INC. The company kept investing through the post-Lehman years because precision instruments smoothed the semiconductor cycle and the semiconductor outlook justified the capacity.

The 2010s were then spent annexing the ground beside the two pillars. Precision cutting blades — the diamond blades that dice wafers and ceramics — were acquired as a business in 2012 and given a Thai plant in 2014, pairing equipment with consumables. In February 2019 the company bought Fujitsu Telecom Networks Fukushima for its charge-and-discharge test systems, entering electrical measurement just as batteries and electric vehicles created demand for it; that November it took the balancer business of SCHMITT INDUSTRIES of the United States and renamed the unit ACCRETECH SBS — its first overseas acquisition in the twenty-seven years since STC.

A Taiwanese application centre opened in 2021 near TSMC and UMC, the TSE reclassification moved the company to the Prime Market in April 2022, and a third major plant opened at Hanno, Saitama, in 2023. Revenue has run with the semiconductor cycle rather than against it — ¥146.8bn in the year to March 2023, ¥134.7bn in 2024, $1.0B (¥151bn) in 2025 at a 19.7% operating margin. Under Yoshida Hitoshi as chairman and Kimura Ryuichi, who took the presidency in 2021 from the semiconductor side of the house, the mid-term plan starting in FY2025 aims to lift semiconductor equipment from about ¥113.5bn toward ¥140bn and to make the two pillars feed each other technically rather than merely coexist.