Aoyama Seisakusho

What Aoyama Seisakusho does

Aoyama Seisakusho Co., Ltd. (株式会社青山製作所) is a privately held Japanese manufacturer of automotive fasteners founded in 1950 and headquartered in Ooguchi-cho, Niwa-gun, Aichi Prefecture, Japan. The company designs and produces bolts, nuts, and specialized fastening components used throughout vehicles, organized into two product lines: Global Standard Products for standardized applications and Advanced Products engineered for electric-vehicle battery systems and mixed-material vehicle structures. Its core competency, marketed as 'Fastening Engineering' (ファスニングエンジニアリング), combines product proposal capability with proprietary surface-treatment and plating know-how, including a globally deployable high-corrosion-resistant water-based surface treatment recognized by Toyota.

The company operates 10 domestic manufacturing and sales bases in Japan and 5 overseas bases, anchored by AOYAMA THAI in Thailand (960 employees, 60-year presence) and a new production facility under construction in India (groundbreaking October 2025). It supplies automotive OEMs and Tier-1 suppliers — primarily Toyota group entities (including Headquarters, Miyoshi, Akei, Hirose, Kyushu, Hokkaido, East Japan, Home, and Industries factories), as well as Honda, Daihatsu, Hino, Isuzu, Aisin, JTEKT, Toyota Auto Body, and Hitachi Automotive Systems — under direct B2B contracts with quote-based, undisclosed pricing. Quality performance is evidenced by repeated Toyota awards including five-consecutive-year zero-defect recognition and acknowledgment for contributing to four consecutive Le Mans victories.

Revenue is generated through hardware sales of precision fasteners under long-standing OEM supply relationships; revenue figures are not publicly disclosed. The company is family-controlled under President Yukiyoshi Aoyama, with no public listing, no disclosed external equity funding, and ownership of multiple wholly-owned subsidiaries including the 2021-acquired Sanyo Plating Industry. Distribution is direct-to-OEM with no intermediary layer, and the company pairs its core manufacturing business with motorsports sponsorships (TOYOTA GAZOO Racing WEC), regional community events (AOYAMA FesTa), and ESG/health-management initiatives (Health Management White 500, Aichi SDGs registration, Toyota Environment Promotion Award).

Name

Aoyama Seisakusho

Legal name

株式会社青山製作所 (Aoyama Seisakusho Co., Ltd.)

Website

https://asj-fasteners.co.jp

Company type

Private

Founded year

1950

Operating status

Operating

Headcount range

1,001–5,000 employees

Short description

Aoyama Seisakusho is a privately held Japanese manufacturer of automotive fasteners — bolts, nuts, and specialized fastening components — supplying primarily Toyota group entities and other Japanese OEMs from 10 domestic and 5 overseas manufacturing bases, including facilities in Japan, Thailand, and India.

Ownership category

akta.pro rank

Headquarters

HQ city

Nagoya

HQ country

Japan

HQ region

Asia

Offices10 records

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

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

Revenue model

1. Automotive Fastener Manufacturing: Design, manufacture, and supply of precision fasteners (bolts, nuts, and specialized fastening components) for automotive applications, including EV-specific fastening solutions and mixed-material structural fasteners. Revenue is generated through direct supply contracts with automotive OEMs and tier-1 suppliers.

Go-to-market motion1 record

Distribution channels1 record

Marketing channels6 records

Core offering

Aoyama Seisakusho designs, manufactures, and supplies precision automotive fasteners — primarily bolts, nuts, and specialized fastening components — for automotive OEMs and tier-1 suppliers. The product portfolio is split into Global Standard Products (standardized fasteners meeting global automotive industry specifications) and Advanced Products (high-performance fastening solutions for electric vehicles, mixed-material structures, and safety-critical applications), supported by in-house surface treatment and plating capabilities.

Product overview

Aoyama Seisakusho is a Japanese fastener manufacturer specializing in bolts, nuts, and related fastening components for the automotive industry. The company offers its products under two main categories: Global Standard Products for standardized automotive applications, and Advanced Products for high-performance engineered solutions. Their core value proposition is 'Fastening Engineering' — combining ideas, technology, and core competencies to deliver products that satisfy functionality, performance, and quality at the highest levels. Products are used throughout vehicles to improve quality and anticipate market needs.

Differentiator

Problem solved

Functional benefit

Products and services

• Fasteners (Bolts, Nuts, and Related Fastening Products) Primary product line of Aoyama Seisakusho, consisting of bolts, nuts, and specialized fastening components used across all parts of automobiles to improve vehicle quality. Offered to automotive OEMs and tier-1 suppliers under two categories: Global Standard Products (standardized fasteners) and Advanced Products (high-performance engineered solutions for EVs and mixed-material structures).
• Global Standard Products (グローバルスタンダード) Standardized fastening solutions designed to meet global automotive industry specifications. Sold to automotive OEMs and tier-1 suppliers requiring widely-spec'd fasteners for vehicle assembly.
• Advanced Products (アドバンスドプロダクト) High-performance engineered fastening solutions developed for electric vehicles (including EV battery systems) and mixed-material vehicle structures. Sold to automotive OEMs for next-generation and safety-critical applications; includes recognized innovations such as the floating nut developed for the new Toyota Prius and globally deployable high-corrosion-resistant water-based surface treatment for the new Toyota Camry.

Quantifiable outcome

• Five consecutive years of zero delivery defects to Toyota Miyoshi/Akei factories
• +2 more outcomes

Named customers20 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

Feature3 records

Partnerships

Two partnerships are on record, tiered core.

• Sanyo Plating Co., Ltd. (三洋鍍金工業)coreOthers · 24 December 2021Sanyo Plating Co., Ltd., an Aichi-based plating processing company, joined the Aoyama Group in December 2021. The companies had a long-standing cooperative relationship, and the capital tie-up was established to combine technical and production strengths for delivering more satisfying products to customers.
• KAMAX-Werke Rudolf Kellermann GmbH & Co.KG (德国KAMAX)coreStrategic or Co-development Partner · 10 February 2009Aoyama Seisakusho and German company KAMAX agreed in February 2009 to a globally comprehensive cooperation including mutual production contracting, joint procurement, and technology exchange, with future consideration of joint venture establishment. Each company's independence is maintained while pursuing expanded customer bases through increased production capacity and avoidance of duplicate investments.

Scale indicators4 records

Recent moves12 records

Expansion highlights6 records

Direct peers

• Agrati Group: Italian Tier-1 automotive fastener manufacturer with global production footprint (Europe, North America, Asia) serving similar OEM customers. Comparable business model of standardized plus engineered fastening components for vehicle assembly.
• Nifco Inc. Japanese Tier-1 manufacturer of plastic fasteners, clips, and functional components predominantly for automotive OEMs. Overlapping customer base and Japanese auto-supplier heritage, though materially larger and more focused on plastic fastening.
• Böllhoff: German family-owned fastening technology specialist offering bolts, thread-locking systems, and assembly solutions to the automotive industry globally. Closely comparable in being a privately held specialist with deep European OEM relationships.
• Fontana Gruppo: Italian fastener manufacturer specializing in bolts, nuts, and engineered fastening solutions for the automotive sector. Similar mid-sized industrial profile with diversified auto OEM customer base and European/Asian manufacturing.
• Meidoh Co., Ltd. Japanese automotive fastener specialist with global manufacturing footprint supplying Japanese OEMs. Comparable mid-sized Japanese player with similar auto-OEM customer concentration and international production strategy.
• LISI Automotive: Division of the French LISI Group and one of the largest global suppliers of engineered fasteners, clips, and assembly solutions to automotive OEMs. Direct competitor for global Tier-1 fastener programs including mixed-material and EV applications.
• KAMAX-Werke Rudolf Kellermann: German automotive fastener specialist and Aoyama's named strategic partner since 2009 for mutual production, joint procurement, and technology exchange. Closest functioning global twin in the high-strength bolt/nut space for auto OEMs.
• Piolax Corporation: Japanese specialty fastener, clip, and spring manufacturer serving Japanese and global automotive OEMs (including Toyota). Closely comparable Japanese auto-fastener specialist with overlapping customer base and similar export-driven model.

Broad incumbents

• Bossard Group: Swiss-listed fastener specialist combining product manufacturing, distribution, and engineering services across industrial customers including automotive. Comparable in fastening-engineering positioning, though larger and more distribution-led.
• Adolf Würth: German global market leader in fasteners and assembly technology with a substantial automotive customer base via its industry division. Much larger and broader; comparable only as a benchmark for fastener-scale economics.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat5 records

Key risks6 records

Key highlights7 records

Customer concentration

• Xx.com/AFD_ID

Revenue estimate

Valuation estimate

Number of profiles

Profiles1 record

Subsidiaries7 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 Aoyama Seisakusho