Kotani Corportion

What Kotani Corportion does

Kotani Corporation (株式会社コタニ) is a Japanese precision forging manufacturer founded in 1970 and headquartered in Kasai City, Hyogo Prefecture. The company produces forged automotive drivetrain components, including transmission gear blanks, bearing races, differential ring gears, CVT components, and hub bearings, using warm forging, hot forging, hot rolling, cold rolling, and orbital forging processes. It holds proprietary patents on warm forging (1988), hot rolling (1994), and hypoid gear production (1999), and operates an integrated forging-to-rolling line that uses residual heat from forging to drive the rolling stage. The company runs 11 factories in Japan (nine at the Kasai headquarters plus two Kasai Minami plants) and a subsidiary in Zhangjiagang, China, with a combined production capacity of 81,165 tons per year.

Kotani's revenue model is B2B sale of forged components to tier-1 automotive suppliers and OEMs. Named customers include AISIN, JATCO, EXEDY, NTN, JTEKT, NSK, NACHI-FUJIKOSHI, Timken, SNR, and Magna Powertrain, and over 90% of revenue comes from auto parts including bearing parts. Sales are conducted directly through a field sales organization, including a regional sales office in Anjo City in the Toyota-area supplier cluster. FY2025 sales reached 204 billion yen (approximately USD 1.36 billion) on a workforce of 464 employees as of June 2026. The company is IATF 16949:2016 certified and operates in the same Japanese precision forging niche as competitors such as Hirschvogel (with which it previously ran a 2007–2011 Polish joint venture that was transferred to Hirschvogel in 2011).

The company is privately held under founding-family control. In June 2025, founder Masahiro Kotani stepped down as Representative Director to become Chairman, with Satoshi Yoshikawa continuing as President and Naomichi Inoue newly appointed as Executive Vice President. The company has pursued steady geographic and capacity expansion: a first overseas subsidiary in Zhangjiagang, China in 2014; a Mexico subsidiary in 2016; and domestic plant buildouts including Plant No. 6 (2017), Plant No. 8 (2018), and Plant No. 9 (2022). Railway bearings represent an adjacent product line beyond core automotive applications. Stated capital was reduced to 100 million yen in 2015 as a balance-sheet restructuring measure.

Name

Kotani Corportion

Legal name

株式会社コタニ

Website

https://kk-kotani.co.jp

Company type

Private

Founded year

1970

Operating status

Operating

Headcount range

11–50 employees

Short description

Kotani Corporation is a Japanese precision forging manufacturer producing automotive drivetrain components—transmission gear blanks, bearing races, CVT parts, and differential ring gears—for tier-1 suppliers including AISIN, JATCO, NTN, and JTEKT. It operates 11 domestic factories and a China subsidiary.

Ownership category

akta.pro rank

Product category

Automotive Forged Components

NAICS

Motor Vehicle Parts Manufacturing (3363), Motor Vehicle Transmission and Power Train Parts Manufacturing (336350)

SIC

Ball & Roller Bearings (3562), Motor Vehicle Parts & Accessories (3714)

akta.pro primary industry

Wheel Hubs, Bearings & Knuckles (Hubs/Bearings/Spindles/Knuckles) (IMACAIAI)

Keywords

• Precision forging
• Automotive transmission parts
• Bearing races
• Differential ring gears
• CVT components

Headquarters

HQ city

Kasai

HQ country

Japan

HQ region

Asia

Offices5 records

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

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

Revenue model

1. Automotive Forged Parts Manufacturing: Manufacturing and sale of forged parts for automotive transmissions and differentials including mission gear blanks, bearing races, differential ring gears, and related components. Revenue derived from OEM supply contracts with major automotive manufacturers.

Go-to-market motion1 record

Distribution channels2 records

Marketing channels4 records

Core offering

Kotani Corporation manufactures precision-forged automotive components for transmissions, differentials, bearings, and constant-velocity joints, including hub bearings, tapered roller bearings, CVT sheaves and shafts, planetary gears, output gears, and hypoid ring gears. The company operates five core manufacturing processes — warm forging, hot forging, hot rolling, cold rolling, and orbital forging — together with in-house die making, heat treatment, machining, and automated warehousing. Products are sold under contract manufacturing arrangements to automotive OEMs and Tier-1 suppliers including AISIN, JATCO, EXEDY, NTN, JTEKT, NSK, NACHI-FUJIKOSHI, Timken, and SNR.

Product overview

Kotani Corporation (株式会社コタニ) is a precision forging manufacturer specializing in automotive drivetrain components. The product portfolio spans three major automotive applications — wheel-end parts (hub bearings, constant velocity joints), transmission parts (tapered roller bearings, CVT pulleys, planetary gears, output shafts), and differential parts (hypoid ring gears, differential drive gears/pinions) — produced through five manufacturing processes: warm forging, hot forging, hot rolling, cold rolling, and orbital forging. A key differentiator is the forging-rolling integrated production line (鍛造・ローリング直結ライン), which continuously connects saw-cutting, forging, hot rolling, and heat treatment in a single automated flow. The company also operates in-house turning/machining, heat treatment, die manufacturing, and automated warehouse facilities. Production is organized across 9 factories at headquarters in Kasai City, Hyogo Prefecture, plus 2 Kasai Minami factories (model factory and inspection/shipment), and 1 overseas factory in Zhangjiagang, China. Annual production capacity is 81,165 tons per year, generating annual sales of 204 billion yen (2025).

Differentiator

Problem solved

Functional benefit

Products and services

• Hub Bearings (Hub I, 2nd and 3rd Generation) Precision-forged hub bearings for automotive wheel applications. Hub I (first generation) uses warm forging and set-forging techniques. Later generations feature more complex shapes with the flange integrated into the bearing structure. Sold to automotive bearing manufacturers such as NTN, JTEKT, NSK, and Timken.
• Constant Velocity Joint Components (Inboard/Outboard Outer Rings, BJ Type, Triport)
• Tapered Roller Bearings (Single Row and Double Row)
• CVT Components (Sheaves, Primary/Secondary Shafts)
• Automatic Transmission Gears and Components (Output Gear, Sun Gear, Flange Companion, Idler & Park Gear, Impeller Hub, One-Way Clutch, Inner Drum Clutch, Reverse Retainer Clutch Boss, Front Ring, AT Sheaves, Transfer Drive Gear)
• Planetary Gear Set Components (Planetary Sun Gear, Planetary Ring Gear, Final Gear for AT/CVT, Annulus Gear)
• Differential Components (Hypoid Ring Gear, Drive Pinion, Drive Gear/Case, Pinion Shaft) Hot-forged and hot-rolled differential components including hypoid ring gears, drive pinion gears, drive gears/cases, and pinion shafts for final drive assemblies. Produced using the company's patented hypoid gear production method and integrated forging-rolling lines. Sold to automotive differential manufacturers including Magna Powertrain.
• Cold-Rolled Bearing Components (Spherical Bearing, Radial Bearing, Hub Sleeve)
• Stainless Steel Couplings
• Railway Bearings

Quantifiable outcome

• Energy reduction through one-heat processing in integrated forging-rolling lines
• +2 more outcomes

Named customers10 records

Segments2 records

Ideal customer profiles1 record

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature5 records

Partnerships

One partnership is on record.

• Hirschvogel Holding GmbHmajorStrategic or Co-development Partner · 1 January 2009Joint venture agreement signed in 2009 with German forging major Hirschvogel Holding GmbH. Kotani Poland operations were transferred to Hirschvogel in 2011 as part of the agreement.

Scale indicators6 records

Recent moves16 records

Expansion highlights4 records

Direct peers

• Asahi Forge Corporation: Japanese automotive forging specialist producing transmission and drivetrain forged components for OEMs. Closely comparable business model and product overlap with Kotani's transmission gear blanks and bearing races.
• Suncall Corporation: Japanese precision forging manufacturer serving automotive drivetrain and electronics markets. Directly comparable to Kotani in forged automotive components, target customer base (Japanese Tier-1s), and Japanese listed mid-cap industrial profile.
• Hirschvogel Holding GmbH: German precision forging major and Kotani's former JV partner in Poland (2009–2011). Closest European peer with overlapping product range in automotive drivetrain forged components and similar integrated-process technology orientation.
• Musashi Seimitsu Industry Co., Ltd. Honda-affiliated manufacturer of CVT components, transmission gears, and constant-velocity joints. Direct overlap with Kotani's transmission and CVT forged/machined components for automotive drivetrains.
• Aichi Forge Co., Ltd. Japanese automotive forging subsidiary of Aichi Steel serving Japanese OEMs and Tier-1s. Direct competitor in precision forging for transmissions, drivetrain, and chassis components with comparable customer base and manufacturing scale.

Regional players

• SeAH Besteel Co., Ltd. Korean specialty steel and forging supplier serving Asian automotive markets. Comparable in automotive forging capability and regional Asian auto-supply positioning, though headquartered outside Kotani's primary Japan/China footprint.

Others

• Nippon Steel Corporation: Japan's largest steelmaker and upstream supplier to the forging industry. While not a direct competitor, it is the primary raw-material supplier to Kotani's hot forging operations and a closely linked industry participant in automotive steel supply chains.

Broad incumbents

• Bharat Forge Limited: India-headquartered global forging leader with extensive automotive drivetrain forging portfolio. Larger and more diversified incumbent serving similar global OEM/Tier-1 customers with comparable forging technology base.
• ThyssenKrupp AG: German industrial conglomerate with significant automotive components and forged-steel products division. Broader incumbent across automotive value chain with overlapping forged drivetrain component offerings to global OEMs.
• Schaeffler Group: German global leader in bearings, transmission components, and chassis parts. While downstream of Kotani in some bearing applications, operates comparable integrated manufacturing of drivetrain components serving the same automotive customers.

Market position

Strengths4 records

Weaknesses4 records

Competitive moat5 records

Key risks5 records

Key highlights6 records

Customer concentration

• Instagraminstagram.com/kotani1974
• LinkedInlinkedin.com/company/kotani-corporation

Compliance3 records

Revenue estimate

Valuation estimate

Number of profiles

Profiles8 records

Subsidiaries1 record

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 Kotani Corportion