What Okamoto Machine Tool Works does

Okamoto Machine Tool Works, Ltd. is a Japanese precision machine tool and semiconductor equipment manufacturer founded in 1926 (incorporated 1935) and listed on the Tokyo Stock Exchange Standard Market under ticker 6125. The company operates two principal business segments: machine tools (surface, form, cylindrical, internal, gear, and combined grinding machines) and semiconductor manufacturing equipment (back grinders, final polishers, CMP systems, slicing machines, and wafer lapping/polishing equipment for silicon and SiC wafers). It holds Japan's No. 1 domestic market share in surface grinding machines and the world's top share in final polishers.

The company's technology base is built on abrasive grain processing expertise accumulated since 1926, combined with a preserved traditional Kisage hand-scraping craftsmanship practice and modern CNC automation. Product capabilities include linear motor-driven ultra-precision form grinders achieving ±1μm contour accuracy and Ra 23nm surface roughness, gantry-type precision surface grinders with 96% material removal rates, and wafer back-grinders with zero-breakage performance for wafers down to 10μm thickness. Production is vertically integrated across the group, from pattern design and casting through machining, painting, and final assembly, with manufacturing facilities in Japan, Singapore, Thailand, and China.

Okamoto generates revenue primarily through direct sales of B2B industrial capital equipment via 9 domestic and 13 overseas sales/service offices, plus aftermarket services (overhauls, retrofits, parts, and service packs) handled in-house and via the Giken subsidiary. Customers span precision mold makers, automotive component manufacturers, bearing and optical component producers, gear manufacturers, and semiconductor wafer fabs (with SUMCO publicly named as a 2023 Supplier Award recipient). In 2024 the company entered a capital and business partnership with Mitsui & Co. via third-party share allocation, with consolidated headcount of 2,229 as of March 2026.

Name

Okamoto Machine Tool Works

Legal name

株式会社 岡本工作機械製作所

Website

https://okamoto.co.jp

Company type

Public

Founded year

1926

Operating status

Operating

Headcount range

1,001–5,000 employees

Short description

Okamoto Machine Tool Works designs, manufactures, and sells precision grinding machines and semiconductor manufacturing equipment from Japan to global industrial manufacturers, mold makers, and semiconductor wafer producers through a direct sales network spanning nine domestic and thirteen overseas offices.

Ownership category

akta.pro rank

Product category

Precision Grinding Machine Tools

NAICS

Machine Tool Manufacturing (333517), Metalworking Machinery Manufacturing (33351)

SIC

Machine Tools, Metal Cutting Types (3541), Metalworkg Machinery & Equipment (3540)

akta.pro primary industry

CNC Machine Tools (Turning, Milling, Machining Centers) (IMAHADAA)

Keywords

• Precision grinding machines
• Semiconductor manufacturing equipment
• Surface grinding technology
• Wafer polishing equipment
• CNC machine tools

Headquarters

HQ city

Annaka

HQ country

Japan

HQ region

Asia

Offices29 records

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

Personnel, Supply Chain, Operations, Technology or R&D, Infrastructure, Marketing or Sales

Revenue model

1. Machine tool manufacturing and sales: Okamoto designs, manufactures, and sells precision grinding machines including surface grinders, form grinders, cylindrical grinders, internal grinders, and combined grinding machines. Products range from general-purpose manual machines to fully automated CNC machines. Revenue is generated through direct sales via domestic and overseas offices, with custom configuration and test grinding demonstrations as part of the sales process.
2. Semiconductor-related manufacturing equipment sales: Semiconductor manufacturing equipment including back grinders (GNX series), final polishers (PNX series), CMP machines (SPP series), slicing machines, ingot grinders, and wafer lapping/polishing machines. Equipment serves wafer processing steps for silicon, SiC, and other semiconductor materials, sold directly to semiconductor manufacturers.
3. Aftermarket services, parts, and overhaul: After-sale services including mechanical repairs, spare parts supply, on-site static accuracy inspections, specified hydraulic oil exchanges, operational re-training, overhaul (precision restoration), and retrofits. Services are provided through the Customer Service Department and group company 技研(Giken). Annual and 3-year service pack plans are offered.

Pricing tiers

Go-to-market motion1 record

Distribution channels3 records

Marketing channels4 records

Core offering

Okamoto Machine Tool Works designs, manufactures, and sells precision grinding machines (surface, form, cylindrical, internal, gear, and combined grinders) and semiconductor manufacturing equipment (wafer back grinders, final polishers, CMP machines, slicers, and ingot grinders). Products range from general-purpose manual machines to fully automated CNC machines with linear motor drives, serving precision mold makers, automotive component manufacturers, optical equipment makers, and semiconductor wafer fabricators. The company also provides after-sale services including overhaul, retrofits, and parts supply.

Differentiator

Problem solved

Functional benefit

Brands

• GRIND-X: Brand name for grinding wheels, grinding fluids, paper filters, hydraulic oils and other consumables and peripheral products.
• GRIND-FILTER
• GRIND-ECO
• GRIND-SMART
• GRIND-MAP
• SELF
• TWIN-BIX
• Quick Touch
• MADOKA II

Products and services

• UPZ-Li Series Ultra-Precision Form Grinding Machines Ultra-precision form grinding machines with linear motor drives for sub-micron contour accuracy and nanometer-level surface roughness, used for micro-precision molding components in mold and die manufacturing.
• PSG Series CNC Precision Surface Grinding Machines CNC precision surface grinding machines including the PSG-CA-iQ series, which incorporates iQ software to automatically generate optimal grinding conditions. Used for precision surface grinding across mold, die, and general manufacturing applications.
• UPG-CHLi Series Gantry-Type Precision Surface Grinding Machines CNC gantry-type precision surface grinding machines capable of handling large workpieces (e.g., 1300×500×100mm) with high material removal rates (96% at 0.1mm infeed). Designed for motor core dies and slot dies. Surface roughness as low as Ra 4.2nm is achievable on the UPG3010CHLi2 model.
• OGM-NCIII Series CNC Precision Cylindrical Grinding Machines CNC precision cylindrical grinding machines with left-right V-V sliding table surfaces, achieving roundness accuracy of 0.1μm and surface roughness of Ra 11nm. Used for high-precision cylindrical components.
• IGM15NCIII-2B Precision Internal Grinding Machine Precision internal grinding machine for high-precision internal diameter grinding of bearings, mechanical components, and other parts requiring tight internal tolerances.
• UGM Series Combined Grinding Machines (Grinding Centers) Combined grinding centers (UGM-V, UGM-GC series) with multiple grinding wheel spindles enabling fully automatic outer diameter, inner diameter, and face grinding in a single setup, reducing setup time and improving productivity.
• HPG500NC High-Precision Form Grinding Machine High-precision form grinding machine for precision mold and die applications requiring tight contour accuracy.
• VRG-DX Series Vertical Rotary Surface Grinding Machine Vertical rotary surface grinding machine for large circular workpieces, enabling high-efficiency surface grinding of round components.
• PSG-SA1 Series Precision Surface Grinding Machine Precision surface grinding machine for general precision surface grinding applications.
• GNX Series Back Grinders for Semiconductor Wafer Manufacturing Creep feed grinding back grinders for semiconductor wafer thinning, achieving zero wafer breakage rate. Supports 200mm and 300mm wafers, including silicon carbide (SiC) power semiconductor wafers, processing wafers down to ultra-thin 10μm thickness.
• Precision Wafer Polishers and Final Polishers (PNX Series) Precision wafer polishers for the critical wafer surface flattening step in semiconductor manufacturing. Handles wafers up to Ø450mm diameter, including silicon, SiC, and glass substrates, down to ultra-thin thicknesses of 10μm. The final polisher product line holds the world's top market share.
• CMP Machines (SPP Series) Chemical mechanical polishing (CMP) machines for semiconductor wafer planarization, achieving high-precision polishing of semiconductor substrates.
• Si Through-Electrode Wafer Fully Automatic Grinding Device Fully automatic grinding device for silicon through-electrode wafers, developed under the JST A-STEP program for advanced semiconductor packaging applications.
• SELF Fully Automatic Surface Grinding System Fully automatic surface grinding system enabling unattended grinding operations for high-mix low-volume production environments.
• Quick Touch On-Machine Measurement System On-machine touch-probe measurement system for in-process dimensional measurement of workpieces during grinding, supporting process control and quality verification.
• iQ Grinding Optimization Software Software that digitizes Okamoto's surface grinding process know-how and automatically generates optimal grinding and dressing conditions based on grinding wheel grit input, integrated into PSG-CA-iQ series machines.
• Machine Tool After-Sale Services, Overhaul and Retrofit Comprehensive after-sale service offerings for Okamoto machines including mechanical repairs, spare parts supply, on-site static accuracy inspections, hydraulic oil exchanges, operational re-training, precision restoration overhauls, and retrofits. Available as annual or 3-year service pack plans through the Customer Service Department and Giken.

Quantifiable outcome

• Zero wafer breakage rate achieved by GNX series back grinders
• +4 more outcomes

Named customers2 records

Segments4 records

Ideal customer profiles3 records

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

AI capability5 records

Feature9 records

Partnerships

Three partnerships are on record, tiered strategic and core.

• Ellison Technologies (米Ellison Technologies社)strategicStrategic or Co-development Partner · 1 January 2025In September 2025, Okamoto signed a memorandum to strengthen its partnership with US-based Ellison Technologies, an Ellison Technologies group company. The enhanced partnership aims to strengthen collaboration in sales and service operations for Okamoto's machine tools in the US market.
• Press Seed (株式会社プレシード)strategicStrategic or Co-development Partner · 1 January 2023Okamoto entered into a capital and business partnership with Press Seed in April 2023, a company engaged in precision measurement and machining technology. The partnership is aimed at strengthening Okamoto's capabilities in precision measurement and expanding technological collaboration in advanced machining.
• Japan Science and Technology Agency (JST) — A-STEP ProgramcoreStrategic or Co-development Partner · 1 January 2016Okamoto's semiconductor equipment development division was selected for the A-STEP (Achievement Staged to Reinforce in-Situ Education and Research; 研究成果最適展開支援プログラム) program administered by the Japan Science and Technology Agency. The program supports the development of semiconductor manufacturing equipment. In October 2025, the Si through-electrode wafer fully automatic grinding device developed under this program was recognized as successfully completed.

Scale indicators8 records

Recent moves14 records

Expansion highlights5 records

Broad incumbents

• DMG Mori Co., Ltd. Global leader in CNC machine tools (turning, milling, additive) with Japan/German roots. Competes with Okamoto for high-precision mold and aerospace customers at a substantially larger scale and broader geographic reach.
• Shibaura Machine Co., Ltd. (formerly Toshiba Machine): Japan-listed precision machinery maker with machine tools, injection molding, and semiconductor/FPD equipment. Comparable to Okamoto across both machine tool and semiconductor equipment business segments, with larger overall scale.
• Makino Milling Machine Co., Ltd. Larger Japanese precision machine tool maker specializing in vertical/horizontal machining centers and EDM. Competes with Okamoto in high-precision mold and die machining customers but with a broader product portfolio and larger scale.
• Amada Machine Tools Co., Ltd. Subsidiary of Amada Group focused on precision surface and profile grinding machines. Direct overlap with Okamoto's surface grinder business, particularly in Japanese mold and die customers, with the backing of the larger Amada parent.

Direct peers

• DISCO Corporation: Japan-listed leader in wafer dicing, grinding, and polishing equipment for semiconductors. Directly comparable to Okamoto's semiconductor equipment division (back grinders, polishers), with stronger global market share but narrower machine-tool exposure.
• United Grinding Group: Swiss/German group comprising Studer, Walter, Schaudt, Mikrosa, and Mägerle — direct competitor to Okamoto in surface, cylindrical, tool, and creep-feed grinding machines, serving the same automotive, aerospace, and tooling customers globally.
• Komatsu NTC Ltd. Subsidiary of Komatsu Group making precision machine tools (grinding, machining) and semiconductor manufacturing equipment. Closely comparable to Okamoto's dual machine-tool + semiconductor-equipment business model with broader automotive industry exposure.
• Sodick Co., Ltd. Japanese precision machine tool maker specializing in EDM, CNC milling, and linear-motor-driven machine tools. Overlaps with Okamoto in CNC precision machining, semiconductor-related equipment, and linear-motor-driven ultra-precision machines.
• Yasda Precision Tools K.K. Japanese specialist in high-precision machining centers and surface grinders. Comparable niche positioning to Okamoto in serving ultra-precision mold, die, and optical component manufacturers, though smaller scale.
• ANCA Group: Australian precision grinding machine specialist (CNC tool and cutter grinders). Comparable to Okamoto in serving precision tooling manufacturers, with stronger global brand recognition in the cutting-tool segment.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat5 records

Key risks6 records

Key highlights7 records

Customer concentration

• YouTubeyoutube.com/@OkamotoCorp1972
• LinkedInlinkedin.com/company/okamoto-machine-tool-works-ltd

Revenue estimate

Valuation estimate

Number of profiles

Profiles12 records

Subsidiaries10 records

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Okamoto Machine Tool Works