USA Piping Solution is a well-trusted manufacturer, exporter, and stockist of SS 321 Seamless Tubes or Stainless Steel 321 Seamless Tubes. Grade 321 is a titanium stabilized austenitic stainless steel, which is resistant to sensitization and intergranular corrosion in welded parts and also in long-term service at temperatures of 425 to 900 degrees C. The alloy SS 321 Seamless Tubes is advantageous for frequent thermal cycled applications because it is stabilized against precipitation of chromium carbides by the titanium content in the alloy. Our seamless tubes are made according to ASTM A213 and ASME SA213 standards, which are made of 321 stainless steel. We have a wide selection of tubes with various outer diameters, wall thickness and lengths and are regularly exporting to customers in the USA, UK, Germany, UAE, Saudi Arabia, Singapore and Australia.
Stainless Steel 321 Seamless Tubes Specifications
Parameter | Details |
|---|---|
Grade | SS 321 / SS 321H |
Standard | ASTM A213 / ASME SA213, ASTM A269, ASTM A511 |
Manufacturing Method | Cold Drawn Seamless / Hot Finished Seamless |
Outer Diameter (OD) | 6.00 mm to 101.60 mm |
Wall Thickness | 0.5 mm to 12.70 mm |
Length | 1 m to 12 m, random or fixed |
Schedule | SCH 5S, SCH 10S, SCH 40S, SCH 80S |
End Finish | Plain End, Beveled End |
Surface | Bright Annealed (BA), 2B, Pickled |
Testing | Hydrostatic Test, Flattening Test, Eddy Current Test, IGC Test |
Certifications | EN 10204 3.1, Mill Test Certificate, Third Party Inspection |
Types of SS 321 Seamless Tubes
Not sure if 321 or 316 fits your application?
Talk to our technical sales team for a grade recommendation.
Request a QuoteChemical Composition of SS 321 Seamless Tubes
Element | SS 321 | SS 321H |
|---|---|---|
Carbon (C) | 0.08% max | 0.04 to 0.10% |
Manganese (Mn) | 2.00% max | 2.00% max |
Silicon (Si) | 0.75% max | 0.75% max |
Phosphorus (P) | 0.045% max | 0.045% max |
Sulfur (S) | 0.030% max | 0.030% max |
Chromium (Cr) | 17.00 to 19.00% | 17.00 to 19.00% |
Nickel (Ni) | 9.00 to 12.00% | 9.00 to 12.00% |
Titanium (Ti) | 5 x C min, 0.70% max | 4 x C min, 0.70% max |
Mechanical Properties of SS 321 Seamless Tubes
Property | SS 321 | SS 321H |
|---|---|---|
Tensile Strength (min) | 515 MPa | 515 MPa |
Yield Strength 0.2% proof (min) | 205 MPa | 205 MPa |
Elongation in 2 in. (min) | 40% | 40% |
Brinell Hardness | 217 HB max | 217 HB max |
Rockwell Hardness | 95 HRB max | 95 HRB max |
Dimensional Tolerances for SS 321 Seamless Tubes (as per ASTM A213)
Parameter | Tolerance |
|---|---|
Outer Diameter (up to 25.4 mm OD) | +/- 0.10 mm |
Outer Diameter (over 25.4 mm to 38.1 mm) | +/- 0.15 mm |
Outer Diameter (over 38.1 mm to 50.8 mm) | +/- 0.20 mm |
Outer Diameter (over 50.8 mm) | +/- 0.25 mm or 0.5%, whichever is greater |
Wall Thickness | +20%, -0% of specified wall |
Length (cut to length up to 6 m) | +6.4 mm, -0 mm |
Straightness | 3.2 mm in 3 m |
Physical Properties of SS 321 Seamless Tubes
Property | Value |
|---|---|
Density | 8.0 g/cm3 |
Melting Range | 1399 to 1427 deg C |
Thermal Conductivity | 16.1 W/m.K (100 deg C) |
Thermal Expansion | 17.2 x 10-6 /K (0 to 100 deg C) |
Electrical Resistivity | 0.72 x 10-6 Ohm.m |
Modulus of Elasticity | 193 GPa |
Magnetic Permeability | Non-magnetic in annealed condition |
Equivalent Grades of SS 321 Seamless Tubes
Grade | UNS No | Swedish SS | Old British BS | JIS | EN No | EN Name |
|---|---|---|---|---|---|---|
SS 321 | S32100 | 2337 | 321S31 | SUS 321 | 1.4541 | X6CrNiTi18-10 |
SS 321H | S32109 | 321S51 | SUS 321H | 1.4878 | X6CrNiTi18-10 |
SS 321 Seamless Tube Size and Weight Chart (ASTM A312)
OD (mm) | Schedule | Wall Thickness (mm) | Weight (kg/m) | Size (in) |
|---|---|---|---|---|
13.72 | 80S | 3.02 | 0.81 | 1/4 |
17.15 | 80S | 3.20 | 1.12 | 3/8 |
21.34 | 80S | 3.73 | 1.65 | 1/2 |
26.67 | 80S | 3.91 | 2.23 | 3/4 |
33.40 | 160 | 6.35 | 4.30 | 1 |
42.16 | 160 | 6.35 | 5.69 | 1 1/4 |
48.26 | 80S | 5.08 | 5.49 | 1 1/2 |
60.33 | 160 | 8.74 | 11.29 | 2 |
73.03 | 80S | 7.01 | 11.59 | 2 1/2 |
88.90 | 160 | 11.13 | 21.67 | 3 |
101.60 | 80S | 8.08 | 18.92 | 3 1/2 |
114.30 | 160 | 13.49 | 34.05 | 4 |
141.30 | 160 | 15.88 | 49.87 | 5 |
168.28 | 120 | 14.27 | 54.75 | 6 |
219.08 | 160 | 23.01 | 112.97 | 8 |
SS 321 Seamless Tube Elevated Temperature Properties
Temperature (F / C) | Yield Strength 0.2% Offset (ksi / MPa) | Tensile Strength (ksi / MPa) | Elongation in 2 inch gauge (%) |
|---|---|---|---|
200 / 93 | 30.2 / 208 | 75.2 / 518 | 39.5 |
400 / 204 | 26.0 / 179 | 66.0 / 455 | 28.0 |
600 / 316 | 23.1 / 159 | 64.2 / 443 | 26.0 |
800 / 427 | 21.2 / 146 | 62.7 / 433 | 25.0 |
1000 / 538 | 21.0 / 145 | 61.3 / 423 | 23.0 |
1200 / 649 | 21.1 / 146 | 54.4 / 375 | 19.5 |
1400 / 760 | 21.1 / 146 | 37.9 / 261 | 23.0 |
1600 / 871 | 16.2 / 112 | 22.5 / 155 | 48.0 |
1800 / 982 | 8.0 / 55 | 11.3 / 78 | 41.0 |
SS 321 Seamless Tube Temperature Range
Grade | Service Temperature Range |
|---|---|
SS 321 Seamless Tubes | 800 deg F to 1650 deg F (427 deg C to 899 deg C) |
SS 321 vs SS 316 Seamless Tubes
Property | SS 321 Seamless Tubes | SS 316 Seamless Tubes |
|---|---|---|
Chromium (Cr) | 17 to 19% | 16 to 18% |
Nickel (Ni) | 9 to 12% | 10 to 14% |
Titanium (Ti) | 0.4 to 0.7% | Not present |
Molybdenum (Mo) | Not present | 2 to 3% |
Density | 7.9 g/cm3 | 7.8 g/cm3 |
Thermal Conductivity at 100 deg C | 16.1 W/m.K | 14.3 W/m.K |
Electrical Resistivity | 0.72 x 10-6 Ohm.m | 0.72 x 10-6 Ohm.m |
Corrosion Resistance | Good | Excellent |
Primary Application | High temperature service, heat exchangers | Marine, chemical, chloride environments |
Applications of SS 321 Seamless Tubes
- Power Generation: Superheater tubes, reheater tubes, steam collecting headers
- Petrochemical: Process piping operating at elevated temperatures, refinery equipment
- Chemical Processing: Reaction vessels, distillation columns, heat exchangers
- Aerospace: Engine exhaust components, firewall tubing
- Pharmaceutical: High purity process piping
- Food Industry: High temperature sterilization lines
- Nuclear: Fuel cladding, coolant circuits
- Automotive: Exhaust manifold tubing (high temperature service)
Equivalent Grades for SS 321 Seamless Tubes
Standard | Grade |
|---|---|
UNS | S32100 |
ASTM | 321 |
DIN / EN | 1.4541 |
EN Name | X6CrNiTi18-10 |
JIS | SUS321 |
BS | 321S31 |
AFNOR | Z6CNT18-10 |
Related Products
- Stainless Steel 321 Pipes and Tubes
- Stainless Steel 321 Welded Tubes
- Stainless Steel 347 Tubes
- Stainless Steel 347 Seamless Tubes
- Stainless Steel 304 Seamless Pipe & Tube
- Stainless Steel 316 Seamless Pipe & Tube
- Stainless Steel 310 Pipes and Tubes
- Stainless Steel Seamless Pipes and Tubes
- ASTM A213 Tubing
Frequently Asked Questions
How is pricing calculated for SS 321 Seamless Tubes?
Pricing depends on OD, wall thickness, length, surface finish, and order quantity. Share your full specification and we'll issue a detailed quote within one business day.
What sizes of SS 321 Seamless Tubes are kept in stock?
We stock common sizes from 6.00 mm to 101.60 mm OD in standard schedules. Larger or non-standard sizes can be produced to order with shorter lead times for bulk quantities.
Is third-party inspection available before shipment?
Yes, we arrange third-party inspection through agencies like SGS, BV, or TUV before dispatch, along with dimensional reports and material test certificates for your records.
Can I get a sample length before placing a bulk order?
Yes, sample lengths can be arranged for first-time buyers to verify quality, dimensions, and surface finish before committing to a full production order.
Looking for SS 321 Seamless Tubes in Custom Sizes?
USA Piping Solution supplies Stainless Steel 321 Seamless Tubes in cut-to-length options, custom OD/WT combinations, and various surface finishes. Call us or submit your RFQ for immediate pricing.
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