SUS 321 Stainless Steel Pipe Specifications, Sizes and Standards
Dec 15, 2025
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What is SUS321 stainless steel equivalent to?
SUS321 stainless steel is equivalent to AISI 321, UNS S32100, and European 1.4541 (X6CrNiTi18-10), offering similar properties to SUS304 but with added titanium for enhanced high-temperature strength and resistance to intergranular corrosion, making it ideal for heat exchangers, furnace parts, and exhaust systems.
| Grade | UNS No | Euronorm | Old British | Japanese JIS | Swedish SS | ||
|---|---|---|---|---|---|---|---|
| Name | No | En | BS | ||||
| 321 | S32100 | X6CrNiTi18-10 | 1.4541 | 58B, 58C | 321S31 | SUS 321 | 2337 |
What is SUS 321 stainless steel tubing?
SUS 321 is a titanium-stabilized austenitic stainless steel, equivalent to AISI 321 / EN 1.4541. The addition of titanium (Ti) prevents chromium carbide precipitation during welding or high-temperature exposure, making SUS 321 particularly suitable for continuous use in environments between 450–870°C.
SUS321 Stainless Steel Pipe & Tube Standards
| Category | Standard |
|---|---|
| SUS321 Stainless Steel Seamless Tube | ASTM A213 / ASME SA213, JIS G3459 |
| SUS321 Stainless Steel Welded Pipe | ASTM A312 / ASME SA312, JIS G3463 |
| SUS321 Stainless Steel Tube for Heat Exchangers | ASTM A249, EN 10217 |
| SUS321 Stainless Steel Chemical Composition | JIS G4303 / ASTM A240 |
| SUS321 Stainless Steel Inspection Certificates | EN 10204 3.1 / 3.2, ISO 9001, SGS, BV |
Stainless Steel 321 Seamless Pipe Standard Specification
| Standard Specification | ASTM A 312/ ASME SA 312/ A790/ SA790/ EN10216-5 |
| Size | ½" to 6" NB Sch 10s, 40s, & 80s, 160s |
| Wall Thickness | 0.1 - 60 mm |
| Length |
Single Random Length 5to7 mtr Double Random Length 10-12 mtr |
| Surface Finish |
Cold Finish, Bright, Polished, Annealing, Pickling, or as per client requirements |
| Standard | JIS, AISI, ASME, ASTM, AMS, GB, DIN, EN, GOST |
| Manufacturing types | Seamless, Welded, ERW, EFW |
| Manufacturing Shapes | Round, Square, Rectangle, Box Section |
| Manufacturing Technology | Hot / Cold Formed |
| Other Grades | S32100,1.4541,SUS321 |
| Technique | Cold Rolled, Hot Rolled |
ASTM A312 Grade TP321 ERW pipe Composition Standard
| 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 |
Stainless Steel 321 Seamless Pipe Mechanical Strength
| 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 % |
SS 321 Pipe HS Code
| Material | HS code |
|---|---|
| SS 321 | 73044900 |
SS 321 Seamless Pipe Temperature Rating
| Properties (MPa) | Temperature Range | |||
|---|---|---|---|---|
| 800°C | 700 °C | 600 °C | ||
| Creep resistance | Rz/100000 | 10 | 22 | 65 |
| Rz/1000 | 30 | 88 | 200 | |
| Rz/10000 | 15 | 48 | 142 | |
| Creep limit | R1/10000 | 10 | 30 | 85 |
| R1/1000 | 15 | 45 | 110 | |
ASME SA 312 TP 321 Tube Tolerance
| NPS | ASTM A312 TP321 OD Tolerance | |||
| + | – | |||
| inch | mm | inch | mm | |
| 1/8~1 1 /2 > 1 1 /2~4 > 4~8 > 8~18 > 18~26 > 26~34 > 34~48 |
1/64(0.015) 1/32(0.031) 1/16(0.062) 3/32(0.093) 1/8(0.125) 5/32(0.156) 3/16(0.187) |
0.4 0.8 1.6 2.4 3.2 4.0 4.8 |
1/32(0.031) 1/32(0.031) 1/32(0.031) 1/32(0.031) 1/32(0.031) 1/32(0.031) 1/32(0.031) |
0.8 0.8 0.8 0.8 0.8 0.8 0.8 |
ASTM A312 Tp321 Seamless pipe Size Chart
| NPS | OD | SCH 5S | SCH 10S | SCH 40S | SCH 80S |
| 1/4 | 13.72 | – | 1.65 | 2.24 | 3.02 |
| 3/8 | 17.15 | – | 1.65 | 2.31 | 3.2 |
| 1/2 | 21.34 | 1.65 | 2.11 | 2.77 | 3.73 |
| 3/4 | 26.67 | 1.65 | 2.11 | 2.87 | 3.91 |
| 1 | 33.4 | 1.65 | 2.77 | 3.38 | 4.55 |
| 1.25 | 42.16 | 1.65 | 2.77 | 3.56 | 4.85 |
| 1.5 | 48.26 | 1.65 | 2.77 | 3.68 | 5.08 |
| 2 | 60.33 | 1.65 | 2.77 | 3.91 | 5.54 |
| 2.5 | 73.03 | 2.11 | 3.05 | 5.16 | 7.01 |
| 3 | 88.9 | 2.11 | 3.05 | 5.49 | 7.62 |
| 3.5 | 101.6 | 2.11 | 3.05 | 5.74 | 8.08 |
| 4 | 114.3 | 2.11 | 3.05 | 6.02 | 8.56 |
SUS 321 Stainless Steel Pipe Price Reference
In the current market, SUS 321 stainless steel pipe prices are generally higher than 304, but competitive compared with molybdenum-containing grades.
| Pipe Type | Price Range (USD/kg) |
|---|---|
| Seamless SUS 321 Pipe | USD 5.5 – 9.0 / kg |
| Welded SUS 321 Pipe | USD 4.6 – 7.8 / kg |
If you have project requirements for ASTM A312 TP321 stainless steel welded pipes, please click the button below to contact us immediately. We would be happy to assist you.
If you have project requirements for SUS321 stainless steel pipes, you are welcome to place an order. GNEE has a large inventory of best-selling products for you to choose from. Available in both seamless and welded forms. For detailed chemical composition and free samples, please contact our factory immediately. We offer competitive prices and excellent service.
The pipes are packaged with waterproof paper and steel straps, meeting standard export sea freight packaging requirements, suitable for various transportation methods, or customized according to customer requirements.
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