共和熱処理 List of Products and Services

Our company conducts "metal heat treatment using vacuum carburizing," which achieves a stable surface hardness in a short time. In March 2025, new equipment including a vacuum carburizing furnace and a cart-type batch furnace was introduced at our Iwate factory. 【Details of the introduced equipment】 ■ Vacuum carburizing furnace (Factory No. 4) Internal dimensions: 600H × 660W × 1200L (same type as the current vacuum carburizing furnace) Processing capacity: 650kg/charge Maximum operating temperature: 1100℃ ■ Cart-type batch furnace (Factory No. 1) Internal dimensions: 1500H × 1200W × 2000L Processing capacity: 2,000kg/batch Maximum operating temperature: 900℃ *We have renewed our company brochure! *For more details, please download the PDF catalog or feel free to contact us.

• others

【Hardness Testing】 At Kyowa Heat Treatment Co., Ltd. Kawaguchi Plant, the measurement of Brinell hardness using a hardness tester has been automated, achieving high precision and speedy quality assurance. The automatic indentation reading device can measure in units of 1/1000 mm, which is not possible with conventional methods. Additionally, due to its high identification capability and speed, it completes readings in 1/20 of the usual time. 【Mechanical Testing】 A system has been established to respond to material testing in emergencies by requesting assistance from public institutions. For more details, please contact us.

• others

We have compiled frequently asked questions regarding heat treatment at the Kawaguchi factory.

• others

For hardness, dimensions, and other inquiries, please contact us. 【Materials Suitable for High-Frequency Hardening】 Carbon Steel ▸ S45C, S50C, S55C Alloy Steel ▸ SCM435, SCM440, SNCM439 Bearing Steel ▸ SUJ2 Stainless Steel ▸ SUS420J2, SUS440C Carbon Tool Steel ▸ SK3 Alloy Tool Steel ▸ SKS3, SKD11

• others

What can be done with shot blasting: - Prevent rust formation - Remove dirt - Strip paint / Improve appearance - Extend the life of paint - Anti-slip

• others

At the Kawaguchi plant of Kyowa Heat Treatment Co., Ltd., we have a total of five furnaces. Our company specializes in mixed processing, and we can respond quickly, especially for annealing and tempering. Additionally, we have processes in place to perform correction work in-house for round bars and plates that may experience deformation. Maximum capacity dimensions for the cart track: 1. Width 3200 × Height 1500 × Length 6300 2. Width 2200 × Height 1500 × Length 8500 *The above are the maximum dimensions. Please feel free to contact us regarding the shape, weight, and heat treatment feasibility of the steel materials.

• others

A new "vacuum carburizing furnace" has been added to the Iwate Factory, Plant No. 4. We are also addressing environmental issues and obtained ISO 14001 in 2015. We will continue to strive for further quality improvement and strengthening of environmental management.

• others

At the Iwate factory, a wide range of processes such as vacuum carburizing, nitriding, vacuum treatment, and vacuum carburizing can be performed, making it essential to implement high-precision quality control quickly and accurately. Our company has established a quality assurance system capable of handling mass production by introducing equipment that can automatically conduct a large number of hardness tests. ★ Automatic Vickers hardness tester ★ Preparation of in-house prototype verification test reports

• others

Starting in 2023, we have introduced a fully automatic carburizing prevention machine, achieving complete automation! The efficiency of processing mass-produced items has increased, allowing for delivery in a short period. Additionally, as the work is fully automated, accuracy has improved! We also accept short lead time and one-off orders.

• others

We achieve mass production and short delivery times through a fully automated line that operates 24 hours a day. 【24-hour operation, automated line equipment】 - Vacuum purge gas carburizing furnace - Vacuum degreasing cleaning machine (hydrocarbon) - Vacuum purge nitriding furnace - Vacuum purge bright annealing furnace - Vacuum carburizing furnace - Fluidized bed atmosphere annealing furnace - Rigid two-tank cleaning machine - Automated vertical warehouse - 24-hour monitoring system

• others

The pit-type gas carburizing and nitriding furnace is a furnace that can perform nitriding treatment by heating in nitrogen gas. It is widely used for surface hardening treatment. Processing purposes: wear resistance, fatigue resistance 【Available treatments】 - Gas carburizing and carburizing nitriding hardening - Oxidation-free hardening and tempering

• Other metal materials

Our company conducts "vacuum carburizing metal heat treatment," which achieves a stable surface hardness in a short time. There is no grain boundary oxidation, and there is no concern about cracking. It allows for low carbon dioxide emissions, making it an energy-efficient and clean process. In addition to improving product lifespan, it also enables processing that is difficult with gas carburizing.

• others

It is possible to perform heat treatment using dedicated jigs. We have also considered minimizing bending in the trolley furnace. With the cooperation of jig manufacturers, we can prepare dedicated jigs, so please feel free to consult with our company, which has many achievements.

• Processing Jig

Heat treatment processing is essential for enhancing the high strength and wear resistance of metal products; however, it is difficult to assess quality from the outside and requires specialized techniques. Our skilled technicians respond to the diverse needs within the industry, such as high functionality and short delivery times.

• Other metal materials

A regular transport service has started operating between the Iwate Factory (54-2 Nakaterabayashi, Ishidoriya-cho, Hanamaki City, Iwate Prefecture) and the Kawaguchi Factory (20-5-5 Ryouke, Kawaguchi City, Saitama Prefecture). The heat treatment technologies that each location specializes in can now be delivered from Tohoku to Kanto. At the Kawaguchi Factory, long parts will undergo carburizing treatment at the Iwate Factory. There is no need for any troublesome sorting; we will handle the sorting at our company.

• others
• Other machine tools

Our company is equipped with a total of five carburizing and nitriding treatment facilities. In addition to nitriding treatment, we can also handle mass production parts for carbon prevention and nitriding work. We pay close attention to both the internal quality and the appearance of our products. If you have any questions, please feel free to contact us.

• Steel

Our company specializes in contract heat treatment processing of metals, accommodating a wide range from large raw materials to fine product parts. We conduct general heat treatment (at the Kawaguchi factory) and surface hardening heat treatment (at the Iwate factory), where our skilled technicians respond to the diverse needs within the industry, such as enhanced functionality and shorter delivery times. Additionally, by connecting our two locations logistically, we can deliver the heat treatment technologies that each site excels in from Tohoku to Kanto! By linking the two locations of the Kyoei Heat Treatment Factory, we can achieve: - Significant reduction in logistics costs - A rapid delivery system with up to three shipments per week - A coordinated response system in case of natural disasters or everyday trouble This enables reductions in transportation costs and shortened delivery times. 【Product Line】 ■ General Heat Treatment - Annealing / Normalizing / Quenching / Tempering ■ Surface Hardening Heat Treatment - Surface hardening - Carburizing quenching - Nitriding - Vacuum heat treatment *For more details, please refer to the related links or feel free to contact us.

• Heating device

At Kyowa Heat Treatment Co., Ltd., we perform "metal heat treatment using vacuum carburizing," which achieves stable surface hardness in a short time. In addition to improving product lifespan, we can also realize processing that is difficult with gas carburizing. This document includes a comparison of test results between carburized pure titanium and untreated samples. [Test Contents] ■ Pure titanium was cut, resin-embedded, polished to a mirror finish, and etched. → A 0.5% hydrofluoric acid solution was used to reveal the metal structure, which was then observed and photographed using a metallurgical microscope. ■ Pure titanium was subjected to ultrasonic cleaning with acetone before testing. → X-ray diffraction measurements were conducted using an X-ray diffraction device (XRD). *For more details, please refer to the PDF document or feel free to contact us.

• Surface treatment contract service

Our company conducts "metal heat treatment using vacuum carburizing," which achieves stable surface hardness in a short time. There is no grain boundary oxidation, and there is no concern about cracking. It enables energy-efficient and clean processing with low carbon dioxide emissions. In addition to improving product lifespan, it can also achieve machining that is difficult with gas carburizing. 【Features】 ■ Carburizing of fine pores is possible ■ High concentration carburizing is easy ■ Carburizing of steel, titanium, and SUS is acceptable ■ Extremely shallow carburizing is possible ■ Refining (microstructural refinement) is possible ★ Internal measurement results are included in the materials. You can view detailed information from the 【Download】 section.

• Surface treatment contract service

Flame hardening in electronic science and industry uses a gas flame as a heat source to rapidly heat the surface of the hardened area for quenching. At first glance, it may seem like a primitive method, but similar to high-frequency heat treatment that utilizes Joule heating, the short heating time prevents decarburization and minimizes surface peeling, which is one of its characteristics. It excels in processing complex shapes and large components, but requires advanced technology for temperature management. To produce industrial products that demand uniformity in small lots with a variety of types and short delivery times, skilled craftsmanship is essential. Our flame hardening has been certified by manufacturers for improving the mechanical properties of automotive parts, aerospace and defense industry components, and main components for observatories, earning us widespread trust. [Features] - Uses a gas flame as a heat source to rapidly heat the surface of the hardened area for quenching. - The short heating time prevents decarburization and minimizes surface peeling. - Collaborates with public research institutions for the "visualization of skilled craftsmanship." *For more details, please refer to the PDF document or feel free to contact us.

• Other Auto Parts

Kyouwa Heat Treatment Co., Ltd. is a comprehensive metal heat treatment manufacturer. Kawaguchi Factory: Handling various machine parts, special steel materials, and cast steel products. Iwate Factory: Handling automotive and vehicle parts, construction machinery, and hydraulic components. We can deliver our specialized heat treatment technologies from Tohoku to Kanto, significantly reducing logistics costs. Additionally, we employ approximately 60 metal heat treatment technicians who accurately respond to high-level customer needs. 【Business Overview】 ■ General metal heat treatment processing of raw materials and heat treatment processing of finished products (Carburizing and quenching, tempering, nitriding, vacuum heat treatment, high-frequency quenching, etc.) 【Facilities】 ▼ Kawaguchi Factory ● No. 5 furnace ● 700t hydraulic press ● 100t crank press ● Turntable shot blast, etc. ▼ Iwate Factory ● Pit-type heat treatment furnace ● Vacuum furnace ● Unmanned heat treatment line ● Shot blast, etc. *For more details, please download the PDF or feel free to contact us.

• Other surface treatment equipment