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Last updated: January 2026
This directory lists 57 nitriding companies across the United States, from general job shops offering gas nitriding for automotive components to highly specialized plasma nitriding facilities catering to complex medical devices and aerospace applications.
Buyers typically engage nitriding companies to solve critical surface engineering challenges: extending tool life, improving wear resistance in friction-heavy applications, enhancing corrosion resistance, and boosting fatigue strength without distorting precision parts. They're seeking specific case depths, precise hardness profiles, and often grappling with how to manage the temper resistance of their base material after nitriding, especially when dealing with specific material grades like H13 or 4140, where the balance between a deep diffusion zone and avoiding excessive white layer formation is crucial.
Nitriding suppliers range from large, multi-process heat treaters with extensive automation and dedicated lines for high-volume parts, to smaller, specialty shops focusing on niche materials, proprietary processes, or unique part geometries. Some facilities specialize primarily in gas nitriding, offering precise control over nitriding potential, while others lean heavily into plasma nitriding for its reduced distortion, selective nitriding capabilities, and ability to process stainless steels without prior activation. Understanding their core process strengths and throughput capabilities is key.
To secure an accurate quote and ensure successful outcomes, buyers must come prepared with detailed material specifications, desired case depth and hardness requirements (e.g., Vickers hardness at specific depths), masking requirements for non-nitrided areas, and any critical post-nitriding dimensional tolerances. Suppliers, in turn, expect a clear understanding of the part's end-use application, its pre-nitrided condition (e.g., stress relieved, hardened and tempered), and any applicable industry standards or certifications like NADCAP or CQI-9 that must be met.
57 companies nationwide
Accurate Steel Treating, Incorporated provides specialized heat treatment services, including Gas Nitriding and Ion Nitriding, for the aerospace industry. Based in South Gate, CA, the company holds Nadcap Accreditation and is approved for thermal processing by major manufacturers, ensuring high-quality metal processing solutions.
Burbank Steel Treating Inc, based in Burbank, CA, provides metal heat treating and thermal processing services. They cater to demanding industrial sectors like Aerospace, Military, Automotive, Electronic, and Medical industries. The company leverages years of experience to deliver high-quality thermal processing solutions, committed to customer service and meeting precise specifications.
Santa Clara, CA-based Byington Steel Treating provides expert heat treating and surface hardening services, including nitriding, carburizing, and carbonitriding. They also offer cryogenic tempering and metal forming. The company serves aerospace, automotive, electronics, and medical industries.
Chicago Flame Hardening is a family-owned company in East Chicago, IN, specializing in comprehensive metal heat treating services. They provide various processes, including nitriding, flame hardening, induction hardening, and carburizing, serving a broad range of industrial applications within the metal-treating industry.
Based in Santa Fe Springs, CA, Continental Heat Treating, Inc. provides advanced thermal processing services, altering metal composition for precise metallurgical properties. With top-quality equipment and experienced personnel, they serve critical sectors including aerospace, defense, energy, and transportation. The company is NADCAP accredited.
Based in Indianapolis, IN, Contour Hardening provides commercial gas nitriding and nitrocarburizing thermal processing. They offer in-house solutions for achieving high surface hardness, repeatable depth, and minimal part distortion. Contour serves aerospace, automotive, agriculture, heavy machinery, and firearms industries with science-based thermal processing.
Based in Torrance, CA, Controlled Thermal Processing Inc. specializes in advanced thermal processing services. They focus on removing manufacturing stresses, improving the cutting properties of tool steels like HSS and carbide, and enhancing material properties such as tensile strength and ductility for industrial applications.
Expanite delivers advanced, sustainable gas-based heat treatment and surface hardening solutions primarily for stainless steel. Their proprietary technology, which includes enhanced nitriding processes, is designed to optimize and significantly improve material performance and durability. They operate facilities internationally, including a key location in Twinsburg, Ohio.
Based in Eastlake, OH, HI TecMetal Group provides comprehensive thermal treatment, heat treating, and metal processing services. Specializing in brazing, heat treating, and welding since 1943, they operate five specialized Northern Ohio locations, serving diverse industries like aerospace, transportation, industrial, and manufacturing.
Based in Elkhorn, WI, Hudapack Metal Treating, Inc. provides commercial heat treating services across three plants. Established in 1985, they offer a full range of solutions including atmosphere hardening, carburizing, induction hardening, annealing, vacuum processing, aluminum processing, and nitriding services.
K&D Heat Treat, established 1990, provides comprehensive heat treatment services from its Houston, Texas facility. Operating 24/7, the company offers metal shot blasting and utilizes various furnace sizes to support industrial clients with reliable solutions. Contact their dedicated sales staff for quotes.
Based in Detroit, MI, Kolene Corporation provides salt bath nitriding systems for ferritic nitrocarburizing processes, offering options for manual or automated operation. The company also delivers commercial processing services for nitriding, alongside field services and lab support. Kolene provides critical replacement parts and maintenance.
Based in Houston, TX, Lark Heat Treating provides a wide variety of heat treatment solutions, including gas nitriding, carbonitriding, and carburizing. Founded in 1978, they serve hundreds of industrial customers, from local machine shops to international petroleum industry companies.
Legacy Heat Treatment, located in Corpus Christi, TX, is a provider of specialized heat treatment services. The company offers a range of processes, including carburizing, carbonitriding, and nitriding, designed to enhance the mechanical properties and durability of metal components for various industrial applications.
Based in Houston, TX, Lone Star Heat Treating Corp. provides extensive heat treating services, including controlled atmosphere case hardening and induction hardening. Established in 1945, they also offer mechanical testing, straightening, and NDT. The company holds AS 9100 and ISO/IEC 17025:2017 accreditations.
Magnum Metal Treating Inc. is a Conroe, Texas-based heat treating company specializing in comprehensive metal treatment solutions. They offer a variety of services, including gas nitriding, carburizing, carbonitriding, hardening, tempering, and annealing. Serving industries such as oil and gas, automotive, power generation, and aerospace, Magnum provides high-quality heat treating from its US facility.
Based in Carol Stream, IL, Metals Technology Corporation provides a range of heat treating services, including Gas Nitriding, vacuum heat treating, and annealing. Operating since 1963, the company also offers support services like straightening and blasting, supported by an in-house inspection lab for quality assurance.
Based in Richland Hills, TX, Modern Heat Treat provides a full range of metal heat treatment services with over 35 years of experience. Specializing in processes like carbonitriding, carburizing, and vacuum heat treating, they serve the aerospace, oil and gas, and construction industries from their 25,000 sq ft facility.
Based in Erie, PA, Modern Industries provides commercial thermal processing and heat treating services, strengthening metals for industrial applications. They also offer precision machining, product design, hydraulics, and laboratory testing for a world-wide customer base.
National Heat Treat operates as a direct provider of heat treatment services, including specialized gas nitriding. This surface hardening process diffuses nitrogen into parts to create a layer of hard nitride particles, serving various industrial applications. The company is based in Houston, Texas.
Nitro Vac Heat Treat provides advanced heat treating solutions, specializing in stainless steel nitriding. With over 50 years of experience, the company serves the aerospace industry, delivering precision and reliability for components. They ensure optimal performance and durability for diverse manufacturing needs.
Metal Plasma Technology, based in Valencia, CA, provides Ion Nitriding and Nitrocarburizing services. They perform case hardening on diverse steel alloys, creating strong, non-brittle surfaces. NADCAP accredited since 2003, the company serves aerospace, defense, power generation, and automotive industries.
Based in Burbank, CA, Quality Heat Treating, Inc. provides professional heat treatment services for industrial clients. The company operates its own facilities, specializing in processes like nitriding to enhance surface hardness and wear resistance of metal components. They serve various commercial applications across the United States.
Ramsey Products specializes in precision surface hardening services for critical industrial components. With over thirty years of experience, the company processes gears, sprockets, pulleys, and shafts. They provide durable, high-performance solutions for various manufacturing needs, focusing on enhancing material properties.
Based in Riverdale, IL, Riverdale Plating & Heat Treating provides comprehensive metal finishing and heat treating services. They specialize in various heat treatment processes, including nitriding, carburizing, hardening, and tempering. The company also offers a range of plating solutions like zinc, phosphate, and electroless nickel for industrial applications.
Based in Fort Worth, TX, Southwest Metal Treating specializes in advanced nitriding services. With over 40 years of experience, they provide plasma/ion nitriding with optional post-oxidation for enhanced durability. The company serves industrial machinery, cutlery and hand tool, and turbine manufacturing sectors.
Based in Portland, OR, Stack Metallurgical Group provides comprehensive thermochemical heat treating services. Specializing in processes like plasma nitriding, vacuum heat treating, and carburizing, the company enhances the hardness and wear resistance of metals and alloys. They serve diverse industrial clients across the United States with their advanced metallurgical solutions.
Based in Cincinnati, OH, Cincinnati Steel Treating Company provides comprehensive heat treating services, including Ferritic Nitrocarburizing (FNC) and Gas Nitriding. With over 80 years of experience, they specialize in improving parts performance. This IATF 16949 and ISO 14001 registered provider also offers carbonitriding, carburizing, and various hardening processes.
Based in Clinton Township, MI, Superior Heat Treat LLC offers commercial heat treatment services. An ISO 9001:2015 certified facility, they specialize in Ferritic Nitrocarburizing (FNC) for green technology components. Services cater to tool and die, machine tool, prototype, short-run production, and military markets.
Texas Heat Treating, Inc., based in Round Rock, TX, offers professional heat treatment services. The company is certified to AS9100D and ISO 9001, and accredited to ISO 17025, ensuring compliance with rigorous industry standards including Nadcap for aerospace applications. They are a direct provider of heat treating solutions.
Based in La Porte, TX, Texas Stress, Inc. provides comprehensive on-site and in-house heat treatment services. They specialize in Ferritic Nitrocarburizing (FNC), a thermochemical nitriding process that enhances surface hardness, wear, and corrosion resistance. The company also offers stress relieving, normalizing, and solution annealing for industrial applications.
Based in Hayward, CA, ThermoFusion Inc. provides comprehensive heat treating and metal processing services. They specialize in a range of processes including annealing, brazing, carburizing, stress relieving, and nitriding. The company operates 24/5, offers secondary operations, and holds Nadcap certification for quality assurance.
Thermtech specializes in advanced heat treatment solutions, including gas nitriding services for various steel components. They enhance material surface layers by introducing nitrogen in an ammonia gas atmosphere, improving hardness and wear resistance. Based in Waukesha, WI, Thermtech provides critical thermal processing for industrial applications.
Based in Dayton, OH, Winston Heat Treating offers vacuum heat treating and gas nitriding services. The company is NADCAP and ISO accredited, serving diverse industries including aerospace, automotive, medical, and tooling with advanced furnaces and a focus on quality.
Based in Houston, TX, Worldwide Heat Treat offers comprehensive heat treating services, including hardening, quenching, tempering, and metallurgy. They utilize enhanced 40-foot furnaces for larger materials and provide convenient pickup and drop-off services throughout the Houston and surrounding areas.
Aalberts Surface Technologies provides a comprehensive range of heat treatment processes and surface technologies from its multiple US facilities. They offer solutions including HIP, brazing, polymer coatings, and reel-to-reel treatments to optimize material properties such as hardness, wear, and corrosion resistance for various industrial applications.
Bodycote is a global provider of heat treatment and thermal processing services for metals and alloys. Specializing in processes like nitriding, carburizing, and vacuum heat treatment, the company enhances material properties such as hardness, fatigue strength, and wear resistance. They serve diverse industrial sectors across numerous facilities in the United States.
Advanced Heat Treat Corp. provides industrial heat treatment services. The company specializes in processes like nitriding, enhancing the properties and durability of metal components. They offer specialized treatments to improve wear resistance, fatigue strength, and corrosion resistance for parts used across diverse manufacturing sectors.
Based in Greenville, SC, Bluewater Thermal Solutions offers heat treating services, specializing in Ferritic nitrocarburizing for metals. This service imparts high surface hardness and improves wear resistance and fatigue resistance. The company focuses on enhancing component durability for industrial applications. Bluewater Thermal Solutions is NADCAP Accredited.
Based in Elmira, NY, Elmira Heat Treating provides comprehensive heat treatment services for industrial clients. They specialize in gas nitriding, a surface hardening process that enhances wear resistance and fatigue strength of steel components. Additional capabilities include carburizing, vacuum heat treating, annealing, stress relieving, and black oxidizing, offering diverse metallurgical solutions.
HTS AmeriTek, LLC offers expert metal heat treatment services from facilities including La Porte, TX. They specialize in precision metal and surface heat treating, along with post-weld heat treatment, to enhance component durability and performance. The company primarily serves refinery, fabrication, petrochemical, and pipeline industries.
Based in Springfield, OH, Parker Trutec, Inc. is a direct provider of specialized nitriding services, including ISONITE® Salt Bath Nitriding, ISONITE® QPQ Nitriding, and Gas Soft Nitriding. They also offer Gas Carburizing/Carbonitriding, neutral hardening, and various surface finishing solutions. With multiple US facilities, the company supports diverse industrial needs.
Based in St. Louis, MO, Paulo specializes in precise and repeatable thermal processing services for mission-critical parts. The company offers a wide variety of heat treatment solutions, applying expertise for diverse industrial needs. Paulo is now part of Aalberts NV.
Precision Thermal Processing, located in Clintonville, WI, provides extensive thermal process and heat treating services. Offerings include hardening, surface treatments, annealing, vacuum processing, and metallurgical analysis. The company serves industries such as transportation, energy, and agriculture, operating with ISO 9001 and ISO 17025 accreditations.
Based in Cranston, RI, Spectrum Thermal Processing specializes in direct thermal processing services. They provide surface enhancement through gas nitriding, low-pressure vacuum carburizing, and ferritic nitrocarburizing for steel components. Additional capabilities include hardening, annealing, brazing, deep freeze, and precision quenching, utilizing advanced atmosphere control.
Supreme Steel Treating Inc., based in South El Monte, CA, has provided comprehensive steel heat treatment services since 1982. Capabilities include hardening, annealing, induction hardening, carbonitriding, precipitation hardening, stress relieving, and cryogenic treatment for various steels and alloys, offering in-house processing.
Based in Greenville, SC, Southwest Heat Treat, a division of Bluewater Thermal, offers specialized heat treatment services for industrial applications. The company provides various processes, including nitriding, from its US facilities and is NADCAP accredited for quality assurance.
Based in Anaheim, CA, Techni Nickel is a full-service metal finishing company. They provide Salt Bath Nitriding (SBN), a thermo-chemical treatment that enhances the wear and corrosion resistance of ferrous metals. Techni Nickel also offers a range of electroplating and coating services.
Woodworth Heat Treating, based in Flint, MI, specializes in thermal processing services, prominently featuring nitride heat treatment and ferritic nitrocarburizing. They also offer Nanowear, Ultrawear, and steam oxide processes. Serving diverse sectors like automotive, oil and gas, and military, the company enhances component strength and wear resistance.
Accurate Ion Technologies offers advanced ion-plasma nitriding services, specializing in surface treatments for industrial components. This company provides specialized solutions to enhance the wear resistance, hardness, and corrosion properties of metals, serving a range of manufacturing needs.
Based in Lakeside, CA, Coating Services Group offers advanced thermal spray and surface finishing services. They provide comprehensive heat treatment solutions, including Gas Nitriding and Plasma Nitriding, alongside vacuum heat treating, carburizing, and tempering. They also offer precision grinding, machining, and engineering support.
Based in Houston, TX, Houston Heat Treat provides comprehensive thermal processing services. Specializing in both gas and ion (plasma) nitriding, the ISO 9001:2015 certified company also offers vacuum hardening, carburizing, annealing, stress relieving, and tempering for industrial components.
Based in South Houston, TX, Houston Plating & Coatings Llc specializes in a broad range of plating and coating services. Offerings include SBN/QPQ nitriding, Electroless Nickel, phosphate, and various spray coatings like Xylan and Epoxy. The company focuses on quality, customer service, and fast turnaround times for industrial clients.
IBC Coatings Technologies provides advanced surface treatment solutions, specializing in Salt Bath Nitriding (SBN), Electroless Nickel Plating, and Thermal Spray Coatings. The company enhances the performance and extends the lifespan of critical components for various industries, utilizing state-of-the-art facilities in St. Louis, Missouri.
Based in Marinette, WI, JGS-Nitriding, LLC. provides advanced plasma ion nitriding, plasma ferritic nitro-carburizing, and Plasox® treatments. Specializing in steel materials, they enhance surface hardness, wear resistance, fatigue strength, and corrosion protection. The company offers reliable, economical, and fast services for clients nationwide.
Peters Heat Treating Inc., based in Belle Vernon, PA, offers comprehensive metal heat treatment services. They specialize in both Gas and Plasma Nitriding, alongside vacuum heat treating, carburizing, and hardening. Serving industrial clients, they enhance the strength and durability of metal components.
Progressive Metal Service specializes in nitriding services, enhancing surface hardness and wear resistance for industrial components. They deliver tailored solutions to meet specific customer needs, improving metal part durability through advanced thermal processing techniques.
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Minimizing distortion during nitriding involves several factors. Look for suppliers who utilize specialized fixturing, vacuum furnaces (for plasma nitriding) which offer better temperature uniformity and slower heating/cooling rates, or who have experience with pre-stress relieving your components. Communicating critical dimensions and tolerances upfront allows the supplier to tailor the process parameters, potentially using multi-stage cycles or specific gas mixtures to reduce thermal shock and internal stresses.
Beyond part geometry, always specify the exact base material grade (e.g., 4140, H13, 17-4 PH), its pre-nitrided heat treatment condition (e.g., hardened and tempered to 30 HRC), desired case depth range, target surface hardness (e.g., 60-65 HRC), and any maximum allowable white layer thickness. Clearly state the application and any areas requiring masking or specific post-processing. Providing engineering drawings with critical dimensions and tolerances is also essential.
Gas nitriding (using ammonia) is typically more cost-effective for high-volume, uniform parts and offers excellent control over nitriding potential, yielding precise case depths and properties. Plasma nitriding (ion nitriding) excels for complex geometries, offers better dimensional stability due to lower process temperatures, allows for selective nitriding, and is often preferred for stainless steels (eliminating activation steps) or when a minimal white layer is critical. The choice depends on material, geometry, desired properties, and cost considerations.
The white layer (compound layer) is the outermost, nitrogen-rich layer formed during nitriding. While it contributes to surface hardness, it can be brittle and prone to spalling or chipping, especially under impact or high stress. For many applications, a thin, compact white layer is acceptable or even desirable. However, excessive or non-uniform white layer can be detrimental. Suppliers manage it by precisely controlling nitriding potential and cycle parameters. Some offer post-nitriding treatments or polishing to remove or thin it, or use proprietary processes designed to minimize its formation. Always discuss your white layer tolerance.
Machining or grinding nitrided surfaces is generally not recommended due to the extreme hardness of the nitrided layer. It typically requires specialized grinding equipment and techniques (e.g., creep feed grinding) and can easily damage the hardened case, compromising its benefits or introducing residual stresses that lead to cracking. Most nitriding is a final surface treatment, with critical dimensions established before the process. If post-nitriding finishing is unavoidable, discuss this with your supplier well in advance to ensure the process parameters account for subsequent material removal and to evaluate if the remaining case depth will still meet requirements.
The success of nitriding is highly dependent on the base material's composition and prior heat treatment. Steels containing nitride-forming elements like chromium, molybdenum, vanadium, and aluminum are ideal as these elements form stable nitrides, which contribute to the hardened diffusion zone. The steel's initial hardness (e.g., hardened and tempered to a specific HRC) also impacts the final nitrided case properties, including hardness and depth. Materials with higher alloy content generally achieve higher surface hardness and maintain it better at elevated temperatures (temper resistance).