極東窒化研究所 List of Products and Services

Kyokuto Nitriding Laboratory Co., Ltd. has specialized in "nitriding treatment" for over 50 years, conducting metal surface hardening and heat treatment for machine parts, aircraft parts, and more. Leveraging our unique perspective as a precision machinery manufacturer and the know-how cultivated through rigorous manufacturing processes, we are engaged in research and development of technologies and systems that only we can provide. We aim to contribute widely to society as a company that earnestly tackles any challenges in various fields of machine parts, which are becoming increasingly complex and demanding high precision. [Business Activities] - Gas nitriding treatment (ordinary nitriding, SP treatment, UN treatment) SP: SP treatment (special nitriding treatment for stainless steel) UN: Ulnite (long-time treatment to thicken the nitrided layer) - Gas soft nitriding treatment (nitrogen-based) - Stress relief annealing treatment - Oxidation-free annealing treatment We are currently offering downloadable technical materials for "Company Profile" and "What is Nitriding?" For more details, please contact us or download the catalog.

• Surface treatment contract service
• Processing Contract

Not sure what to choose? Solve the troubles of design engineers! Case studies of gas nitriding applications categorized by industry, part name, material, and nitriding treatment. From a list of achievements organized into three categories, you can quickly understand when to choose gas nitriding treatment. Gas nitriding, gas soft nitriding, carburizing, high-frequency hardening, thermal spraying, coating, hard chrome plating. Among various surface hardening treatments, gas nitriding has been continuously chosen for many years due to its excellent balance. We have compiled a list of the achievements of gas nitriding treatment, which boasts a high repeat rate, detailing the fields, parts, and materials for which it is selected. 【Reasons for Continued Selection】 - Compared to other surface hardening treatments, it has a lower processing temperature, resulting in less deformation. This may eliminate the need for subsequent correction processes. - Unlike methods such as coating or plating that involve adhesion, it hardens organizationally, reducing the risk of peeling. - It does not soften in high-temperature environments (around 200°C) like carburizing or high-frequency hardening. - Since it is processed in a gas atmosphere, it has less variation compared to physical hardening methods and can achieve deep hardening within the inner diameter. For more details, please download the catalog or contact us.

• Other surface treatment equipment

SP treatment is an effective process for austenitic stainless steel and is useful for preventing corrosion in soldering equipment and solder baths made from lead-free materials. Traditionally, nitriding treatment for stainless steel typically improves wear resistance but has the drawback of deteriorating corrosion resistance. However, SP treatment can enhance wear resistance without compromising corrosion resistance. **Features of SP Treatment** SP treatment is a type of nitriding process that is effective for austenitic stainless steels (such as SUS304, 310, 316). It forms a special nitrided layer, known as the SP layer, while maintaining a passive film (oxide film). This layer has a different structure from the typical nitrided compound layer. It excels in both wear and corrosion resistance and has the following characteristics: - It has a hardened layer with a hardness of HV1000 or higher. - Corrosion resistance does not decrease (it does not rust even after 30 days of salt spray testing). - It is processed at a lower temperature (below 450°C) than traditional nitriding, resulting in even less deformation. Currently, technical materials on nitriding, titled "What is Nitriding," can be downloaded for free. For more details, please download the catalog or contact us.

• Surface treatment contract service

The "Nitriding Treatment Q&A Collection" introduces nitriding treatment technology, which is one of the surface effect methods for steel through heat treatment, demonstrating effectiveness in improving wear resistance, fatigue resistance, corrosion resistance, and heat resistance. From basic explanations of the treatment process and characteristics to various questions such as "Nitrided steel is a special steel, but what is special steel?" "Can cast iron be nitrided?" "What are the advantages and disadvantages of gas nitriding?" we provide answers. [Contents] ■ What is nitriding treatment ■ Surface hardness and depth of hardness layer ■ Origin of nitriding technology ■ Nitriding treatment process ■ Characteristics of gas nitriding treatment ■ Nitriding treatment Q&A *For more details, please refer to the PDF document or feel free to contact us.

• Surface treatment contract service
• Special Steel

I will introduce the differences between "gas nitriding treatment" and "gas soft nitriding treatment." "Gas nitriding method" is a technique that achieves a high-hardness diffusion layer on the surface of steel through the diffusion of active nitrogen. It is performed on parts that require higher strength and precision, and is often used for high-grade materials such as nitrided steel and die steel. On the other hand, "gas soft nitriding method" was developed as an alternative technology to salt bath nitriding during the time when environmental issues arose from salt bath nitriding. It is used for treating lower-grade materials primarily made of carbon steel. [About gas nitriding] - Material: High-grade steel (SACM, SKH, SKD, SCM, SUP) - Desired structure: Diffusion layer (compounds of Al, Cr, and N) - Depth of hardened layer: Deep (0.1 to 1.0 mm) - Surface hardness: High (HV 700 to 1300) - Treatment time: Long (25 to 200 hours) *For more details, please refer to the PDF document or feel free to contact us.

• Surface treatment contract service
• Special Steel

We would like to introduce the "nitriding treatment for stainless steel" conducted at the Far East Nitriding Research Institute, which specializes in nitriding treatment primarily in the Kanto and Tokai areas. Stainless steel is a type of steel that excels in corrosion resistance. During the nitriding process, the entry of nitrogen is hindered by the passive film of chromium oxide on the surface, necessitating an activation treatment. To achieve a stable treatment layer, our company employs a combination of physical removal methods such as shot blasting and chemical removal methods. 【Chemical Removal Methods】 ■ Gas Nitriding Treatment - Does not require ensuring glow discharge - No need for shape, loading amount, or size classification - Provides a stable treatment layer ■ SP Treatment - Has a hardened layer of HV1000 or higher - Processed at lower temperatures than nitriding treatment, resulting in less deformation - Does not reduce corrosion resistance *For more details, please download the PDF or feel free to contact us.

• Surface treatment contract service
• Special Steel

Steel suitable for nitriding includes "nitrided steel," as well as "chromium-molybdenum steel," "stainless steel," and "die steel." Each type of steel has its own suitable nitriding treatment conditions, and the differences in conditions lead to different applications. 【Features】 ◎ Chromium-molybdenum steel (SCM), nickel-chromium-molybdenum steel (SNCM) ■ Nitriding treatment conditions are almost the same as those for nitrided steel ■ The hardness distribution of the nitrided layer is looser than that of nitrided steel and reaches the hardness of the base material ■ Very little thermal deformation ■ Often used for gears because high hardness is not required *For more details, please refer to the PDF document or feel free to contact us.

• Surface treatment contract service
• Special Steel

In the "nitriding treatment" that strengthens the surface of steel, the hardness distribution changes depending on the treatment time and temperature. As the temperature increases, the surface hardness decreases. Additionally, as the treatment time increases, the nitrided layer becomes thicker, generally accompanied by a thicker brittle compound layer. [Features] ■ Hardness distribution changes with treatment temperature and time ■ Surface hardness decreases as temperature increases ■ Nitrided layer becomes thicker with longer time, but hardness does not change much *For more details, please refer to the PDF document or feel free to contact us.

• Surface treatment contract service
• Special Steel

"Nitrided steel" is a product handled by the Far East Nitriding Research Institute, which specializes in nitriding treatment primarily in the Kanto and Tokai areas. This product is a type of special steel that has one or more metal elements added to carbon steel to facilitate nitriding. It has high tensile strength and toughness, making it extremely excellent. 【Metal Element Composition Ratio of Nitrided Steel】 ■ Carbon: 0.40–0.50% ■ Silicon: 0.15–0.50% ■ Manganese: 0.60% or less ■ Chromium: 1.30–1.70% ■ Molybdenum: 0.15–0.30% ■ Aluminum: 0.70–1.20% *For more details, please refer to the PDF document or feel free to contact us.

• Special Steel

"Nitriding treatment" is a surface hardening process that strengthens the surface of steel. Our company performs "gas nitriding treatment," which achieves a deep and stable hardened layer. It results in minimal thermal deformation and can significantly reduce the need for polishing. Often, it can be used without polishing. This process improves the material's fatigue resistance, and particularly, the high compressive residual stress of the nitrided layer significantly enhances the fatigue resistance of notched areas. 【Features】 - Surface hardening treatment that strengthens the surface of steel - Minimal thermal deformation, allowing for reduced polishing - High wear resistance, with almost no hardness reduction at temperatures up to 500°C - Sufficient corrosion resistance against superheated steam up to around 550°C - Low tendency for galling with counterpart materials in sliding parts - Gas nitriding has fewer environmental and health safety issues *For more details, please refer to the PDF document or feel free to contact us.

• Surface treatment contract service
• others

The Kyokuto Nitriding Research Institute Co., Ltd., which conducts gas nitriding treatment, annealing treatment, and more, will explain the relationship between nitriding treatment time, treatment temperature, and hardness (nitrided steel). A diagram shows the hardness distribution based on the nitriding treatment temperature. As the temperature increases, the surface hardness decreases. We have summarized the "nitriding treatment (SACM645) treatment time of 30 hours" in a table, and the "hardness transition curve of nitrided steel (SACM645)" is presented in a graph for explanation. *For more details, please download the PDF or feel free to contact us.

• Processing Contract
• Surface treatment contract service

Nitriding treatment is classified as one of the surface hardening methods in heat treatment. It is a process in which nitrogen diffused from the surface of steel combines with various metallic elements to form hard nitrides, thereby hardening the surface of the steel. The purpose of nitriding treatment is to improve wear resistance, fatigue resistance, corrosion resistance, and heat resistance. Here, we introduce the characteristics of nitriding treatment and gas nitriding as surface hardening treatments. 【Characteristics of Each Surface Hardening Method (Excerpt)】 ■ Nitriding Depth of hardened layer: ○ / Hardness: ○ / Fatigue resistance: ○ / Deformability: ○ / Wear resistance: ◎ / Spalling resistance: ◎ / Heat resistance: ○ / Corrosion resistance: ○ ■ Carburizing Depth of hardened layer: ◎ / Hardness: ○ / Fatigue resistance: ○ / Deformability: △ / Wear resistance: ○ / Spalling resistance: ○ / Heat resistance: △ / Corrosion resistance: △ ■ Siliconizing Depth of hardened layer: ○ / Hardness: ○ / Fatigue resistance: △ / Deformability: △ / Wear resistance: ○ / Spalling resistance: ○ / Heat resistance: ◎ / Corrosion resistance: ◎ ■ Flame Hardening Depth of hardened layer: △ / Hardness: △ / Fatigue resistance: △ / Deformability: △ / Wear resistance: ○ / Spalling resistance: ○ / Heat resistance: △ / Corrosion resistance: △ *For more details, please download the PDF or feel free to contact us.

• Surface treatment contract service
• Processing Contract

Nitriding treatment is a chemical surface hardening method of surface hardening heat treatment, which combines with various metal elements to form hard nitrides that harden the surface. The purpose of nitriding treatment is to improve wear resistance, fatigue resistance, corrosion resistance, and heat resistance. The most popular special steel that is easy to nitridize is SACM645 (commonly known as nitriding steel), which contains Al, Cr, and Mo. Other suitable materials for nitriding include chromium-molybdenum steel, nickel-chromium-molybdenum steel, and stainless steel. [Contents] - What is gas nitriding? - History of nitriding - Characteristics of nitriding treatment and gas nitriding treatment as surface hardening processes - About nitriding steel - Relationship between treatment time, treatment temperature, and hardness For more details, please contact us or download the catalog.

• Processing Contract
• Surface treatment contract service

Kyokuto Nitriding Research Institute Co., Ltd. has specialized in "nitriding treatment" for over 50 years, conducting metal surface hardening and heat treatment for machine parts, aircraft components, and more. Leveraging our unique perspective as a precision machinery manufacturer and the know-how cultivated through rigorous manufacturing processes, we are engaged in research and development of technologies and systems that only we can provide. We aim to contribute widely to society as a company that sincerely tackles any challenges in all fields of machine parts, which are becoming increasingly complex and demanding high precision. 【Business Activities】 ○ Gas nitriding treatment (ordinary nitriding, SP treatment, UN treatment) 　SP: SP treatment (special nitriding treatment for stainless steel) 　UN: Ulnite (long-time treatment to thicken the nitrided layer) ○ Gas soft nitriding treatment (nitrogen-based) ○ Stress relief annealing treatment ○ Oxidation-free annealing treatment For more details, please contact us or download our catalog.

• Surface treatment contract service
• Processing Contract