Premium Stainless Steel 321/321H Forged Pipe Fittings by Ratnadeep Steel & Engg. Co.
Ratnadeep Steel & Engg. Co. is a leading manufacturer, exporter, and supplier of premium-quality Stainless Steel 321 / 321H Forged Pipe Fittings. These fittings are produced from titanium-stabilized austenitic stainless steels using precision forging processes to ensure high mechanical strength, excellent dimensional accuracy, and reliable long-term performance. Our SS 321 and 321H forged fittings are extensively used in high-temperature and moderately corrosive environments where structural stability is critical.
Stainless Steel 321 and 321H grades are specifically designed to resist carbide precipitation during welding and prolonged exposure to elevated temperatures. Titanium stabilization prevents intergranular corrosion, while the higher carbon content in 321H improves creep strength and stress rupture properties. These forged fittings are supplied in socket weld and threaded configurations, providing secure, pressure-tight joints in demanding operating conditions.
SS 321 / 321H forged pipe fittings deliver excellent resistance to oxidation, thermal fatigue, and corrosion at high temperatures. Their compact size and high pressure tolerance make them ideal for use in heat exchangers, exhaust systems, refinery piping, petrochemical processing units, power generation plants, and other high-temperature service applications.
- SS 321/321H Socket Weld Elbow
- UNS S32100 / S32109 Threaded Forged Elbow
- DIN 1.4878 Stainless Steel Forged Elbow
- ASME SA182 SS F321H 45° & 90° Elbow
- ASME SA182 SS 321H Socket Weld Tee
- ASTM A182 SS 321 Forged Equal Tee
- DIN 1.4541 Reducing Tee
- UNS S32109 Unequal & Threaded Tee
- ASTM A182 F321 Threaded Equal Cross
- UNS S32100 / DIN 1.4541 Forged Cross
- ASME SA182 SS 321H Socket Weld Cross
- SS 321 Threaded, Reducing & Unequal Cross
- DIN 1.4541 Threaded Full Coupling
- UNS S32100 Forged Full Coupling
- ASME SA182 SS 321H Socket Weld Full Coupling
- ASTM A182 SS 321 Full Coupling
- ASTM A182 F321 SS Socket Weld Half Coupling
- UNS S32100 / S32109 Half Coupling
- ANSI B16.11 SS 321 Threaded Half Coupling
- UNS S32100 Forged Pipe End Cap
- ASTM A182 F321 SS Socket Weld Pipe Cap
- ASME SA182 SS 321H Forged Pipe End Cap
- SS 321 Threaded Pipe Cap
- UNS S32100 Socket Weld Union
- ANSI B16.5 SS 321 Union
- ASTM A182 F321 Threaded Union
- ASME SA182 SS 321/321H Forged Union
- UNS S32100 Threaded Bushing
- ANSI B16.36 SS 321 Hex Head Bushing
- ASTM A182 F321 Stainless Steel Threaded Bushing
- ASME SA182 SS 321/321H Forged Bushing
- UNS S32100 Threaded & Socket Weld Nipple
- ASTM A182 F321 Swage & Pipe Nipple
- ASME SA182 SS 321 Hex Nipple
- SS 321/321H Screwed Pipe Nipple
CHEMICAL COMPOSITION OF STAINLESS STEEL 321/321H FORGED PIPE FITTINGS
| Element | Cr | Ni | C | Si | Mn | P | S | N | Ti | Fe |
|---|---|---|---|---|---|---|---|---|---|---|
| 321 | min:17.0 max:19.0 |
min: 9.0 max:12.0 |
max:0.08 | max:0.75 | max:2.0 | max:0.045 | max:0.03 | max:0.10 | min:5*(C+N) max:0.70 |
Balance |
| 321H | min:17.0 max:19.0 |
min: 9.0 max:12.0 |
min:0.04 max:0.10 |
min:18.0 max:20.0 |
max:2.0 | max:0.045 | max:0.03 | max:0.10 | min:5*(C+N) max:0.70 |
Balance |
MECHANICAL PROPERTIES OF ASME SA403 SS WP321 / 321H FORGED PIPE FITTINGS
| Grade | Tensile Strength ksi (min.) | Yield Strength 0.2% Offset ksi (min.) | Elongation – % in 50 mm (min.) | Hardness (Brinell) MAX |
|---|---|---|---|---|
| 321/321H | 75 | 30 | 40 | 217 |
SPECIFICATION OF STAINLESS STEEL 321/321H FORGED FITTINGS
| Specifications | ASTM A182 / ASME SA182 |
|---|---|
| Dimension Standard | ASME B16.11, MSS-SP-79, MSS-SP-83, MSS-SP-95, MSS-SP-97, BS3799 |
| Size | 1/8″ NB to 4″ NB |
| Type | Socketweld Fittings, Screwed-Threaded Fittings (NPT or PT Type) |
| Rating Pressure | Threaded End – 2000 / 3000/ 6000 LBS. Socket-weld End – 3000 / 6000/ 9000 LBS. |
321/321H STAINLESS STEEL ASTM A403 FORGED FITTINGS EQUIVALENT GRADES
| STANDARD | UNS | WNR. | EN | JIS |
|---|---|---|---|---|
| SS 321 | S32100 | 1.4541 | X6CrNiTi18-10 | SUS 321 |
| SS 321H | S32109 | 1.4878 | X12CrNiTi18-9 | SUS 321H |
PHYSICAL PROPERTIES OF ASTM A403 STAINLESS STEEL 321/321H PIPE FITTINGS
| Density lbm/in³ | Coefficient of Thermal Expansion (min/in) °F | Thermal Conductivity BTU/hr-ft-°F | Specific Heat BTU/lbm-°F | Modules of Elasticity (annealed)²-psi |
|---|---|---|---|---|
| at 68 °F: 0.286 | at 68 – 212°F: 9.2 at 68 – 1832°F: 20.5 |
at 200°F: 9.3 | at 32 – 212°F: 0.12 | in tension (E): 28 × 10⁶ |
💡 Practical Difference in Use
Use Stainless Steel 321 / 321H Forged Pipe Fittings when: resistance to intergranular corrosion, oxidation, and reliable mechanical strength at elevated temperatures are required in compact piping systems subjected to continuous or cyclic heat exposure. → Example: heat exchangers, furnace components, refinery piping, exhaust systems, and high-temperature chemical process lines.
Applications of SS 321 / 321H Forged Pipe Fittings
Stainless Steel 321 and 321H Forged Pipe Fittings are titanium-stabilized grades designed for high-temperature service, offering excellent resistance to oxidation and carbide precipitation.
- Heat Exchangers & Thermal Systems: High-temperature socket weld and threaded connections.
- Petrochemical & Refining: Hot process piping and reformer units.
- Power Generation: Boiler connections and exhaust piping systems.
When to Choose SS 321 / 321H?
These grades are selected for forged fittings exposed to elevated temperatures where weld integrity and thermal stability are essential.
Choose SS 321 / 321H when:
- Operating temperatures exceed the limits of SS 304 / 304L
- Welded joints are exposed to prolonged high-temperature service
- Titanium stabilization is required to prevent carbide precipitation
- Higher carbon 321H is needed for improved creep strength
- Used in compact, high-temperature forged piping systems
Usage Guide for SS 321 / 321H Forged Pipe Fittings
Directional flow change with strong welded joints in high-temperature applications.
Choose Socket Weld Elbow when
- 45° or 90° direction change is required
- High-pressure or corrosive service is involved
- Leak-proof socket weld joints are critical
- Compact and durable connections are needed
Creates branch connections in high-temperature corrosion-resistant piping systems.
Choose Tee when
- Flow must be split into branch lines
- Equal or reduced outlet sizes are required
- Threaded or socket-weld connections are used
- Used in chemical, marine, or hygienic systems
Four-way flow distribution in high-temperature corrosive service piping.
Choose Cross when
- Flow must be split in multiple directions
- Compact threaded piping layouts are used
- Used in chemical or marine applications
- Strong, corrosion-resistant threaded joints are required
Joins two pipes of the same size in high-temperature corrosive environments.
Choose Full Coupling when
- Pipe extension or repair is required
- Inline threaded connections are used
- High mechanical strength is needed
- Corrosion-resistant, leak-tight joints are essential
Single-end connection welded to equipment or piping.
Choose Half Coupling when
- Branch or instrument connections are required
- Used in chemical, pharma, or marine systems
- Strong and compact welded joints are needed
- Excellent corrosion and oxidation resistance is critical
Seals the end of high-temperature corrosion-resistant threaded pipelines.
Choose Cap when
- Pipe ends must be closed or isolated
- Used for pressure testing or future expansion
- Leak-proof termination is required
- Exposure to corrosive fluids or high-temperature environments exists
Allows easy disconnection in high-temperature corrosion-resistant piping systems.
Choose Union when
- Frequent maintenance or dismantling is required
- Leak-tight threaded joints are important
- Used in chemical, pharma, or marine services
- Corrosion and oxidation resistance at joints is critical
Threaded size reduction in high-temperature corrosive piping systems.
Choose Bushing when
- Pipe size reduction is required
- Space-saving threaded transitions are needed
- Used in chemical or marine pipelines
- Resistance to corrosion and crevice attack is essential
Short threaded connection for high-temperature corrosion-resistant piping systems.
Choose Nipple when
- Joining two female-threaded components
- Compact pipe extensions are required
- Used in chemical, marine, or high-temperature process lines
- Resistance to corrosion and oxidation is essential
Our Forged Pipe Fittings are manufactured using advanced forging processes and undergo extensive quality checks to ensure flawless dimensional accuracy, durability, and long service life. Each fitting is thoroughly inspected using key NDT techniques such as radiographic testing (RT), ultrasonic testing (UT), hydrostatic testing, and visual/dimensional examination. We also perform detailed chemical composition analysis and mechanical property testing to ensure material compliance with strict industry standards.
Throughout the forging and finishing stages, every forged fitting is monitored closely to eliminate defects such as misalignment, surface irregularities, and wall-thickness variations. This ensures perfect joint integrity and high-performance reliability in pipelines carrying high temperatures, pressures, and corrosive media. All our forged fittings fully comply with ASME, ASTM, MSS-SP, and related global specifications, making them a preferred choice for critical piping systems worldwide.
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