Stainless Steel 321 Seamless Pipe Specifications

SS 321 seamless pipes covering standards, dimensions, and lengths are mentioned in the table listed below.

Parameter Details
StandardASTM A312 / ASME SA-312, ASME B36.10, ASTM A999 / ASME SA-999, ASTM A1016 / ASME SA-1016
NPS Range1/2 inch to 12 inch
Outside Diameter21.3 mm to 323.8 mm
Schedules5S, 10S, 40S, 80S, 120, 160
Length6 metres (20 feet); custom-cut available
Dimensional StandardASME B36.19

Stainless Steel 321 Seamless Pipe Sizes

Stainless Steel 321 pipes are available in the sizes, schedules and lengths mentioned in the table given below:

Parameter Details
ProductSS 321 Seamless Pipes
Size Range1/2 inch (12.7 mm) to 12 inch (323.8 mm) NPS
Schedules Available5S, 10S, 40S, 80S, up to 160
Standard Length6 metres (20 feet)

Stainless Steel 321 Seamless Pipe Weight Chart

Weight per metre for common NPS sizes across schedules 10S, 40S, and 80S is mentioned in the table below:

NPS OD (mm) Sch 10S WT (mm) kg/m Sch 40S WT (mm) kg/m Sch 80S WT (mm) kg/m
1/2 inch21.32.111.002.771.273.731.62
1 inch33.42.772.093.382.504.553.24
2 inch60.32.773.933.915.445.547.48
4 inch114.33.058.366.0216.078.5622.32
6 inch168.33.4013.847.1128.2610.9742.56
8 inch219.13.7619.968.1842.5512.7064.64
12 inch323.84.5735.9710.3179.7312.7097.43

Stainless Steel 321 Seamless Pipe Price

SS 321 seamless pipe prices in India range from approximately Rs. 380-450 per kg and $1,000 to $7,000 per metric ton internationally, depending on outside diameter, wall thickness, schedule, and order quantity. International pricing varies with nickel spot rates. Contact Sachiya Steel International for current rates.

Chemical Composition of Stainless Steel 321 Seamless Pipes

The chemical composition of SS 321 (UNS S32100), along with its proportion, is mentioned in the table below:

CarbonC
0.08% max
ManganeseMn
2.00% max
PhosphorusP
0.045% max
SulphurS
0.030% max
SiliconSi
1.00% max
ChromiumCr
17.0-19.0%
NickelNi
9.0-12.0%
TitaniumTi
5x(C+N) min, 0.70% max
NitrogenN
0.10% max

Mechanical Properties of Stainless Steel 321 Seamless Pipes

The mechanical properties of SS 321 seamless pipe, including tensile strength and elongation, are listed in the table below:

75 / 515
ksi / MPa (min)
Tensile Strength
30 / 205
ksi / MPa (min)
Yield Strength
35%
(min)
Elongation
Property Value Unit
Tensile Strength (min)515 (75)MPa (ksi)
Yield Strength, 0.2% offset (min)205 (30)MPa (ksi)
Elongation in 2 inch (min)35%
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Equivalent Grades of Stainless Steel 321 Seamless Pipes

International designation equivalent to SS 321 seamless pipes is listed in the table below:

Standard / Country Designation
UNSS32100
Germany / Europe (EN)EN 1.4541 / X6CrNiTi18-10
Japan (JIS)SUS 321
United Kingdom (BS)321S31
Russia (GOST)08Kh18N10T
China (GB)06Cr18Ni11Ti
Sweden (SS)SS 2337
France (AFNOR)Z6CNT18-10

Stainless Steel 321 Seamless Pipe Industrial Applications

321 stainless steel seamless pipes serve 4 major sectors where high-temperature corrosion resistance and creep strength are critical.

Oil and Gas Industry

SS 321 seamless pipes handle refinery piping and heat exchanger tubing in crude distillation units.

Chemical Processing

Used for reactor transfer lines and exhaust ducting in nitric acid production plants.

Power Generation

Used in boiler superheater piping in thermal power plants.

Aerospace and Exhaust Systems

Found in turbo manifolds and engine exhaust collectors.

Stainless Steel 321 vs 304 Seamless Pipes

The key difference between SS 321 Seamless Pipe and SS 304 Seamless Pipe is the presence of titanium. The table below explains it in detail.

Parameter SS 321 Seamless Pipe SS 304 Seamless Pipe
Base CompositionAustenitic stainless steel with titanium stabilisation (modified 304)Standard austenitic stainless steel (no stabilising elements)
Key Alloying ElementTitanium (Ti) addedNo titanium or stabilising element
Sensitisation ResistanceResistant to sensitisation in the 427-816 C rangeSusceptible to sensitisation in the 427-816 C range
Intergranular CorrosionExcellent resistance due to titanium stabilisationProne after prolonged high-temperature exposure
High-Temperature PerformanceSuitable for continuous service above 425 CNot recommended for prolonged high-temperature exposure
Thermal Cycling ResistancePerforms well under repeated thermal cyclingLower resistance under cyclic heating conditions
Recommended ApplicationHigh-temperature piping, heat exchangers, thermal cycling environmentsGeneral-purpose piping under moderate temperature conditions

Stainless Steel 321 vs SS 316 Seamless Pipes

The table below explains the difference between Stainless Steel 321 vs SS 316 Seamless Pipes in detail.

Property / Criteria Stainless Steel 316 (SS 316) Stainless Steel 321 (SS 321)
Key Alloying Element2-3% MolybdenumTitanium (Ti stabilised)
Primary AdvantageExcellent resistance to chloride pitting and crevice corrosionSuperior resistance to intergranular corrosion at high temperatures
Corrosion Resistance FocusMarine and chloride-rich environmentsHigh-temperature oxidation and sensitisation resistance
Temperature SuitabilityModerate to high temperaturesContinuous service above 425 C
Best Application EnvironmentsMarine, coastal, chemical processing with chloridesHigh-temperature piping, heat exchangers, thermal processing
LimitationReduced performance in prolonged high-temperature exposureLower resistance to chloride environments compared to 316
Recommended Use CaseUse in chloride-rich or marine environmentsUse in continuous high-temperature service (>425 C)

Shipping & Packaging

Main export packaging setup Heavy-duty wooden boxes Packing
Export Packaging Standard

We strictly follow seaworthy export handling standards to protect SS 321 seamless pipe from transit damage, moisture ingress, and surface contamination during long-distance dispatch.

  • Heavy-duty wooden boxes with moisture barrier lining
  • HDPE stretch film wrapping on all bundles
  • Plastic end caps on threaded and plain-end pipes
  • Silica gel desiccants to minimize moisture exposure
  • ISPM-15 fumigated wooden packaging for export
shipping preparation Pipe Bundle Yard Staging
Shipping packaging Container End-Cap Protection
Shipping stock Wrapped Export-Ready Bundles

We Export Worldwide

Sachiya Steel International supplies stainless steel products to major industrial markets across North America, Europe, the Middle East, Asia and Africa with export-ready documentation and logistics support.

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Frequently Asked Questions:

What is the Price of SS 321 Seamless Pipe? +
Prices range from Rs. 380-450 per kg in India and $1,000 to $7,000 per metric ton based on size, wall thickness, and quantity. International pricing depends on nickel market rates.
Is ASTM A312 Seamless or Welded? +
ASTM A312 covers both seamless and welded austenitic stainless steel pipes. SS 321 is available in both forms under this specification.
What is 321 Seamless Pipe Made Of? +
321 seamless pipe contains 17.0-19.0% chromium, 9.0-12.0% nickel, and titanium as a stabilising element. The titanium prevents intergranular corrosion in high-temperature service.
Is 321 Stainless Seamless Pipe better than 304 for High-Temperature Service? +
Yes. SS 321 adds titanium to prevent sensitisation at 427-816°C. Type 304 doesn’t contain titanium and loses corrosion protection after prolonged exposure above 425°C.
What sizes are SS 321 Seamless Pipes available in? +
Available from 1/2” to 12” NPS (21.3 mm to 323.8 mm OD) in schedules 5S through 160. Standard length is 6 metres (20 feet).
Can SS 321 and 321H Seamless Pipes be Dual-Certified? +
Yes. SS 321 (UNS S32100) allows carbon up to 0.08%, while 321H (UNS S32109) requires 0.04-0.10%. When actual carbon falls in the 0.04-0.08% overlap, dual certification to both grades is possible.
What is the Maximum Service Temperature for SS 321 Seamless Pipes? +
Stainless Steel 321 seamless pipes retain oxidation resistance up to 816°C (1500°F) for continuous service. Intermittent service is possible up to 870°C (1600°F).

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