Sun Kogyo Begins Operation of Mass Production Equipment for Wear-Resistant 'Ultra-Hard Chrome Plating' in June

Sun Kogyo Co., Ltd. (Headquarters: Iida City, Nagano Prefecture; President and CEO: Takeo Kawakami), a specialist in plating technologies, has introduced large-scale mass production equipment for 'ultra-hard chrome plating' with exceptional wear resistance. Full-scale operations began today, June 18, 2026, to meet the increasing demand for high-precision and high-durability components driven by the electrification of automobiles and advancements in semiconductor manufacturing equipment.

This new equipment enables mass production of ultra-hard chrome plating—offering approximately twice the hardness and five times the wear resistance of conventional hard chrome plating—on precision components for manufacturing equipment up to 700–800 mm in length. The system is designed with future scalability in mind, and the company plans to gradually expand its capabilities to accommodate large, long rolls up to 2,500 mm in length.

Figure 1: Newly introduced ultra-hard chrome plating bath

Background of New Technology Introduction: Evolution of EV and Semiconductor Industries and the Call for a Sustainable Society

In recent years, the widespread adoption of electric vehicles (EVs), rapid advancements in semiconductor technology, and the rising demand for precision manufacturing equipment have expanded at an unprecedented pace. As a result, components used in these fields now require ultra-high precision and exceptional durability. In particular, rolls used in lithium-ion battery electrode production, precision film stretching rolls, and parts for semiconductor wafer manufacturing equipment are highly sensitive to even minor wear, which can significantly impact product quality and production efficiency, necessitating frequent maintenance and replacement.

While conventional hard chrome plating has contributed to improved wear resistance, cutting-edge industries now demand further technological breakthroughs to meet increasingly stringent requirements for precision and operational efficiency.
Moreover, with growing global awareness of the UN Sustainable Development Goals (SDGs), the manufacturing sector faces increasing pressure to move away from disposable products and embrace longer product lifespans to promote efficient resource use and reduce environmental impact. In response to these industrial challenges and societal demands, Sun Kogyo has developed 'ultra-hard chrome plating' that surpasses conventional plating technologies. With the introduction of this mass production equipment, the company is now positioned to deliver new value by applying this advanced technology to large-scale products.

Key Features of 'Ultra-Hard Chrome Plating'

Unprecedented Hardness and Wear Resistance in Wet Plating:

Conventional hard chrome plating typically achieves a Vickers hardness of Hv800–1,000. Through heat treatment at 400°C, ultra-hard chrome plating reaches a Vickers hardness of Hv1,800 and a Rockwell C hardness of HRC79—approximately twice that of conventional hard chrome plating. This exceptional hardness results in a surface highly resistant to scratches, a rarity among wet plating methods.

Additionally, ultra-hard chrome plating exhibits a lower coefficient of friction compared to conventional hard chrome, resulting in approximately five times greater wear resistance. This significantly reduces maintenance frequency for mechanical components such as lithium-ion battery processing rolls and film stretching rolls, where wear-induced precision degradation is a critical issue, thereby enhancing equipment uptime.

Coating That Hardens Further with Higher Heat Treatment:

While conventional hard chrome plating softens at elevated temperatures, ultra-hard chrome plating continues to harden as the heat treatment temperature increases, reaching Hv2,100 at 600°C. This property makes it suitable for a wide range of industrial applications requiring both high hardness and thermal resistance.

High Corrosion and Chemical Resistance:

The plating is more resistant to rust than high-phosphorus electroless nickel plating, which is already known for its excellent corrosion resistance. It also demonstrates strong resistance to various chemicals, including sulfuric acid, ammonia, and sodium hydroxide.

Crack-Free Coating:

At thicknesses of 3μm or less, the coating does not develop the cracks commonly associated with conventional hard chrome plating. Its excellent release properties make it ideal for mold surface treatments.

Figure 4: Heat treatment temperature dependence of ultra-hard chrome plating film hardness

Benefits from the Start of Mass Production Equipment

Expanded Capability for Large and Long-Sized Products:

With the introduction of this equipment, plating is now possible on various shaped products up to 700 mm in length (800 mm for aluminum materials).

Maximum dimensions (iron material): 450 mm (width) × 450 mm (height) × 700 mm (length)

Maximum dimensions (stainless steel material): 300 mm (width) × 450 mm (height) × 700 mm (length)

Maximum dimensions (aluminum material): 300 mm (width) × 450 mm (height) × 800 mm (length)

The ultra-hard chrome plating bath is sufficiently large, and with future equipment upgrades, plating on long rolls up to 2,500 mm in length and special-shaped components will become possible.

Cost Advantage and Support for Low-Volume, High-Mix Production:

As a wet process (electroplating) that does not require large vacuum chambers, this technology offers significant cost advantages, especially for large components.

It also flexibly supports low-volume, high-mix production of various complex-shaped parts, providing comprehensive support from prototyping to mass production.

Prototyping Services Now Available:

Starting today, prototyping services are available. For details, please contact us via our official website.

URL: https://www.sun-kk.co.jp/

Future Outlook: Contributing to a 'Sustainable Society' and 'Industrial Advancement' Through Long-Life Technologies

Sun Kogyo developed 'ultra-hard chrome plating' to shift from a 'disposable' model to a 'long-life, reuse' circular economy. The introduction of this large-scale plating bath enables contributions to larger products and a broader range of industries that were previously difficult to serve. Moving forward, the company will continue relentless technological innovation and proactive equipment investment to further advance surface treatment technologies that underpin industrial development.

[About Sun Kogyo Co., Ltd.]

Founded in 1949, Sun Kogyo has developed and provided essential surface treatment technologies for the semiconductor, automotive, and industrial machinery sectors. With 40 plating lines capable of handling over 20 types of plating, ISO 9001 and IATF 16949 certification, and awards such as the Minister of Education, Culture, Sports, Science and Technology Prize and the Minister of Health, Labour and Welfare Prize, the company supports Japan's manufacturing industry with high-quality and advanced technological capabilities.

Headquarters: 2148-186 Nishihirami Oshibara, Iida City, Nagano Prefecture

Founded: 1949

Representative: President and CEO Takeo Kawakami

Capital: 90 million JPY

Business: Development and provision of plating, passivation, and other surface treatment technologies for semiconductor equipment, automotive parts, and industrial machinery.

Official Website: https://www.sun-kk.co.jp/

[Inquiries Regarding This Announcement]

Sun Kogyo Co., Ltd.

Sales Department: Haruki Kawai

TEL: +81-265-78-4190

Email: a.kawai@sun-kk.co.jp

Corporate Planning Department: Naoko Kashio

TEL: +81-265-98-7940

Email: n.kashio@sun-kk.co.jp