Machuca Fittings, located in Kuala Lumpur, Malaysia, is a reliable manufacturer and supplier of Stainless Steel 321/321H Forged Fittings, crafted for durability and exceptional performance in high-temperature environments. These fittings—like elbows, unions, couplings, tees, and plugs—are specifically designed to withstand intergranular corrosion and oxidation, even in the toughest service conditions. Stainless Steel 321 is stabilized with titanium, while 321H features a higher carbon content, which enhances creep strength and boosts resistance to thermal stress. Machuca Fittings prides itself on precision engineering, adherence to global standards, and top-notch quality, making their 321/321H forged fittings perfect for applications in the chemical, petrochemical, power generation, and refining industries.
Specifications ASTM A182 & ASME SA182
Standard ASME 16.11, MSS SP-79, 83, 95, 97, BS 3799
Size 1/8” NB to 4” NB (Socketweld & Screwed-Threaded)
Class 2000 LBS, 3000 LBS, 6000 LBS, 9000 LBS
Type Socketweld Fittings, Screwed-Threaded Fittings
Forged Fittings Items : 45 Deg Elbow, 90 Deg Elbow, Forged Tee, Union, Full Coupling, Half Coupling, Cross, Cap, Swage Nipple, Plug, Bush, Welding Boss, Hexagonal Nipple etc.
Type Socketweld Fittings, Screwed-Threaded Fittings
Grade 321 / 321H UNS (S32100, S32109), DIN (1.4541, 1.4878)
The Stainless Steel 321/321H Forged Fittings are made from chromium-nickel austenitic stainless steel, stabilized with titanium (321) and further enhanced with higher carbon content (321H). This unique composition helps prevent carbide precipitation during welding and offers strong resistance to intergranular corrosion. They boast excellent tensile and creep strength, high oxidation resistance, and stability at temperatures reaching up to 870°C. SS 321 is known for its outstanding weldability and toughness, while SS 321H provides improved strength at high temperatures, making these grades ideal for thermal cycling and long-term elevated service in critical environments.
| Grade | C | Mn | Si | P | S | Cr | N | Ni | Ti |
| SS 321 | 0.08 max | 2.0 max | 1.0 max | 0.045 max | 0.030 max | 17.00 – 19.00 | 0.10 max | 9.00 – 12.00 | 5(C+N) – 0.70 max |
| SS 321H | 0.04 – 0.10 | 2.0 max | 1.0 max | 0.045 max | 0.030 max | 17.00 – 19.00 | 0.10 max | 9.00 – 12.00 | 4(C+N) – 0.70 max |
| Density | Melting Point | Tensile Strength | Yield Strength (0.2%Offset) | Elongation |
| 8.0 g/cm3 | 1457 °C (2650 °F) | Psi – 75000 , MPa – 515 | Psi – 30000 , MPa – 205 | 35 % |
Machuca Fittings is a leading supplier of Stainless Steel 321/321H Forged Fittings in Kuala lumpur, Malaysia. We offer an extensive range of Stainless Steel 321/321H Forged Fittings, renowned for their excellent corrosion resistance and high strength, which makes them perfect for demanding industrial applications like chemical processing, marine environments, and high-temperature systems. With a commitment to quality and reliable delivery, we ensure our clients receive top-tier products tailored to meet the specific needs of various industries.
We provide products that come with both mill test certificates and third-party test certificates, ensuring the highest standards of quality and compliance.
| STANDARD | WERKSTOFF NR. | UNS | JIS | EN |
| SS 321 | 1.4541 | S32100 | SUS 321 | X6CrNiTi18-10 |
| SS 321H | 1.4878 | S32109 | SUS 321H | X12CrNiTi18-9 |
Choose Stainless Steel 321/321H Forged Fittings from Machuca Fittings for superior quality, exceptional corrosion resistance, and reliable performance in extreme conditions. We offer customized solutions backed by expert support and industry experience.
Stainless steel 321/321H forged fittings offer many advantages, including resistance to high temperature oxidation and corrosion, making them ideal for use in high-temperature environments The addition of titanium stabilizes the material, especially prevents sensitivity and intergranular corrosion in welds. These fittings have excellent strength, high tensile and yield characteristics, and excellent formability, ensuring durability and long-term performance in critical applications Stainless steel 321H, with a high carbon content of 1,000. for higher strength at higher temperatures. Overall, they are highly reliable in the petroleum, aerospace, and power sectors.
Yes, custom sizes for Stainless Steel 321/321H Forged Fittings are available at Machuca Fittings. We offer tailored solutions to meet your specific requirements, ensuring optimal performance for your projects. For more information, please contact us at sales@machucafittings.com
| Fitting Schedule/Class | Pipe Size – Pipe Fitting | Fitting Connection Type | Pipe Fitting Material | Max. Pressure |
|---|---|---|---|---|
| Class 150 | 1/2″ | FNPT | Stainless Steel 321 | 150 psi |
| Class 150 | 1/2″ | FNPT | Stainless Steel 321 | 150 psi |
| Class 150 | 1/2″ | Forged | Forged Stainless Steel 321 | 275 psi |
| Class 150 | 1/2″ | Welded | Stainless Steel 321 | 150 psi |
| Class 150 | 3/4″ | FNPT | Stainless Steel 321 | 150 psi |
| Class 150 | 3/4″ | FNPT | Stainless Steel 321 | 150 psi |
| Class 150 | 3/4″ | Forged | Forged Stainless Steel 321 | 275 psi |
| Class 150 | 3/4″ | Welded | Stainless Steel 321 | 150 psi |
| Class 150 | 3/4″ | Welded | Stainless Steel 321 | 150 psi |
| Class 150 | 1″ | FNPT | Stainless Steel 321 | 150 psi |
| Class 150 | 1″ | FNPT | Stainless Steel 321 | 150 psi |
| Class 150 | 1″ | Forged | Forged Stainless Steel 321 | 275 psi |
| Class 150 | 1″ | Welded | Stainless Steel 321H | 150 psi |
| Class 150 | 1″ | Welded | Stainless Steel 321 | 150 psi |
| Class 150 | 1-1/4″ | FNPT | Stainless Steel 321 | 150 psi |
| Class 150 | 1-1/4″ | FNPT | Stainless Steel 321 | 150 psi |
| Class 150 | 1-1/4″ | Forged | Forged Stainless Steel 321 | 275 psi |
| Class 150 | 1-1/4″ | Welded | Stainless Steel 321H | 150 psi |
| Class 150 | 1-1/4″ | Welded | Stainless Steel 321H | 150 psi |
| Class 150 | 1-1/2″ | FNPT | Stainless Steel 321 | 150 psi |
| Class 150 | 1-1/2″ | FNPT | Stainless Steel 321 | 150 psi |
| Class 150 | 1-1/2″ | Forged | Forged Stainless Steel 321H | 275 psi |
| Class 150 | 1-1/2″ | Welded | Stainless Steel 321H | 150 psi |
| Class 150 | 1-1/2″ | Welded | Stainless Steel 321 | 150 psi |
| Class 150 | 2″ | FNPT | Stainless Steel 321 | 150 psi |
| Class 150 | 2″ | FNPT | Stainless Steel 321 | 150 psi |
| Class 150 | 2″ | Forged | Forged Stainless Steel 321H | 275 psi |
| Class 150 | 2″ | Welded | Stainless Steel 321 | 150 psi |
| Class 150 | 2″ | Welded | Stainless Steel 321 | 150 psi |
| Class 150 | 2-1/2″ | FNPT | Stainless Steel 321 | 150 psi |
| Class 150 | 2-1/2″ | FNPT | Stainless Steel 321 | 150 psi |
| Class 150 | 2-1/2″ | Forged | Forged Stainless Steel 321 | 275 psi |
| Class 150 | 2-1/2″ | Welded | Stainless Steel 321H | 150 psi |
| Class 150 | 2-1/2″ | Welded | Stainless Steel 321 | 150 psi |
| Class 150 | 3″ | FNPT | Stainless Steel 321 | 150 psi |
| Class 150 | 3″ | FNPT | Stainless Steel 321 | 150 psi |
| Class 150 | 3″ | Forged | Forged Stainless Steel 321H | 275 psi |
| Class 150 | 3″ | Welded | Stainless Steel 321 | 150 psi |
| Class 150 | 4″ | FNPT | Stainless Steel 321 | 150 psi |
| Class 150 | 4″ | FNPT | Stainless Steel 321 | 150 psi |
| Class 150 | 4″ | Forged | Forged Stainless Steel 321H | 275 psi |
| Class 150 | 4″ | Welded | Stainless Steel 321 | 150 psi |
| Class 150 | 4″ | Welded | Stainless Steel 321 | 150 psi |
| Class 150 | 6″ | FNPT | Stainless Steel 321 | 150 psi |
| Class 150 | 6″ | FNPT | Stainless Steel 321 | 150 psi |
| Class 150 | 6″ | Welded | Stainless Steel 321H | 150 psi |
| Class 150 | 6″ | Welded | Stainless Steel 321 | 150 psi |
| DN-NPT | MAJOR DIAMETER MM | TAPPING DRILL SIZE MM | TPI | PITCH MM |
|---|---|---|---|---|
| 1/16″ | 7.895 | 6.00 | 27 | 0.941 |
| 1/8″ | 10.242 | 8.25 | 27 | 0.941 |
| 1/4″ | 13.616 | 10.70 | 18 | 1.411 |
| 3/8″ | 17.055 | 14.10 | 18 | 1.411 |
| 1/2″ | 21.223 | 17.40 | 14 | 1.814 |
| 3/4″ | 26.568 | 22.60 | 14 | 1.814 |
| 1″ | 33.228 | 28.50 | 11.5 | 2.209 |
| 1¼” | 41.985 | 37.00 | 11.5 | 2.209 |
| 1½” | 48.054 | 43.50 | 11.5 | 2.209 |
| 2″ | 60.092 | 55.00 | 11.5 | 2.209 |
| 2½” | 72.699 | 65.50 | 8 | 3.175 |
| 3″ | 88.608 | 81.50 | 8 | 3.175 |
| 3½” | 101.316 | 94.30 | 8 | 3.175 |
| 4″ | 113.973 | 107.00 | 8 | 3.175 |
| 5″ | 141.300 | 134.384 | 8 | 3.175 |
| 6″ | 168.275 | 161.191 | 8 | 3.175 |
| 8″ | 219.075 | 211.673 | 8 | 3.175 |
| 10″ | 273.050 | 265.311 | 8 | 3.175 |
| 12″ | 323.850 | 315.793 | 8 | 3.175 |
These Stainless Steel 321/321H Forged Fittings find extensive use in industries that demand resistance to heat, oxidation, and corrosive substances. In chemical and petrochemical plants, they are essential for piping systems that transport acids and aggressive fluids. Power generation facilities and refineries utilize them in boilers, superheaters, and heat exchangers where high-temperature performance is crucial. In the aerospace and automotive industries, they are preferred for exhaust systems and components that face thermal stress. Additionally, the marine and oil & gas sectors rely on them for their durability and ability to withstand harsh conditions. Their performance in high-temperature and corrosive environments makes them a top choice across various applications.
Get in touch with one of our Technical Sales Representatives to request a quote or get answers to any questions you may have.








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