321 Stainless Steel Pipe – Titanium-Stabilised High-Temperature Champion for 870 °C Service
When your piping system must survive the 425–850 °C danger zone, 321 Stainless Steel Pipe is the only logical choice. The deliberate addition of titanium (≥5×C) locks up carbon as harmless TiC, preventing chromium depletion and intergranular corrosion during welding or long-term thermal exposure. This austenitic grade offers creep rupture strength to 870 °C, full weldability without post-weld anneal, and excellent oxidation resistance—making 321 Stainless Steel Pipe the first choice for aircraft exhaust manifolds, furnace risers, refinery cat-crackers, and thermal oxidizer stacks worldwide.
321 Stainless Steel Pipe – Seamless & 321 Stainless Steel Welded Pipe, ASTM A312 TP321/321H, Ready Stock
Key Features & Benefits
- Titanium stabilised (Ti ≥ 5×C) – immunity to sensitisation 425–850 °C
- Continuous service to 870 °C; intermittent to 900 °C with minimal scaling
- Excellent creep & stress-rupture strength above 600 °C
- Superior weldability – no post-weld stabilising heat treatment required
- Available in both seamless and 321 stainless steel welded pipe forms
- Full compliance – ASTM A312, A213, A269, A358, EN 1.4541, PED 2014/68/EU
- Hygienic, non-porous surface – meets FDA, USP Class VI requirements
Technical Specifications
Table 1 – Chemical Composition (ASTM A312)
| Element | 321 % | 321H % |
|---|---|---|
| Cr | 17.0–19.0 | 17.0–19.0 |
| Ni | 9.0–12.0 | 9.0–12.0 |
| Ti | ≥5×C | ≥4×C |
| C | ≤0.08 | 0.04–0.10 |
| Mn | ≤2.00 | ≤2.00 |
| Si | ≤1.00 | ≤1.00 |
| P | ≤0.045 | ≤0.045 |
| S | ≤0.030 | ≤0.030 |
| Fe | Balance | Balance |
Table 2 – Mechanical & Elevated-Temperature Properties
| Property | Room Temp. | 650 °C | 870 °C |
|---|---|---|---|
| Tensile Strength | ≥515 MPa | ≥320 MPa | ≥150 MPa |
| Yield Strength (0.2 %) | ≥205 MPa | ≥150 MPa | ≥85 MPa |
| Elongation in 2" | ≥40 % | ≥28 % | ≥30 % |
| Hardness HRB | ≤92 | — | — |
| Density | 8.0 g/cm³ (0.289 lb/in³) | — | — |
| Thermal Expansion | 17.2 µm/m·K (20–100 °C) | — | — |
Size Range & Types
Full range from 1/8" to 48" – seamless and 321 stainless steel welded pipe.
| NPS | OD (mm) | Sch | WT (mm) | Length (m) | Type |
|---|---|---|---|---|---|
| 1/8" | 10.3 | 10S/40S/80S | 1.24–2.24 | 6 | Seamless |
| 3" | 88.9 | 10S/40S/80S | 2.11–7.62 | 6/12 | Smls / Welded |
| 6" | 168.3 | 10S/40S/80S | 2.77–7.11 | 6/12 | Smls / Welded |
| 12" | 323.8 | 10S/40S/80S | 3.96–12.7 | 6/12 | Smls / Welded |
| 48" | 1219 | 5S/10S/20/40S | 6.35–25.4 | 3–12 | Welded (SAW) |
Custom lengths, cut-to-size, and bevel ends available.
Product Range & Market Info
As one of the largest 321 stainless steel pipe manufacturers in China, we operate a 150 000 t/year mill with four continuous mandrel mills and seven multi-stand plug mills producing 321 stainless steel welded pipe and seamless pipe from 6 mm to 1219 mm OD. Our 200 000 m² facility keeps 40 000 t of ready stock, ensuring immediate availability for 321 stainless steel pipe suppliers and 321 stainless steel pipe wholesale buyers worldwide. Whether you need one bundle of 6" Sch 40S or a full vessel of 20" × 12 m SAW pipe, our mill-direct pricing and PED-certified quality give you the competitive edge. Contact our export team today for the most updated 321 stainless steel pipe wholesale quotation and downloadable mill test certificates.
Specialty products include 321 stainless steel pipe cap – elliptical, flat, and dished heads from ½" to 48" manufactured in-house under our 321 stainless steel pipe cap company division.
Main Applications
- Aircraft & piston-engine exhaust systems, turbo-charger ducts
- Furnace & boiler tubes, radiant tubes, muffles, baskets
- Refinery cat-crackers, thermal oxidizers, flare stacks
- Superheater tubes, reheater supports, EGR piping
- High-temperature chemical processing, expansion joints
- 321 stainless steel pipe cap for pressure vessels and heat exchangers
Professional 321 Stainless Steel Pipe Cap Company – Custom Sizes from ½" to 48", Mill-Direct Supply
Why Choose Us – Mill-Direct Advantages
- PED 2014/68/EU & TÜV certified mill – EN 10204 3.1 & 3.2 MTC supplied
- 150 000 ton annual capacity – 5-day lead time for standard sizes
- In-house 321 stainless steel pipe cap production – elliptical, flat, and dished heads
- Same-day cutting, beveling, threading – lengths 3–12 m, tolerances ±0.2 mm
- Real-time 321 stainless steel pipe wholesale portal – updated daily at 08:00 CST
- Global export to 70+ countries – fumigation-free crates, vessel booking, insurance
Leading 321 Stainless Steel Pipe Manufacturers & Suppliers – Wholesale Prices, Fastest Delivery to 70+ Countries
Grade & Type Comparison Table
| Grade/Type | Ti % | Mo % | Max Temp (°C) | Weld Post-Treat | Pressure Rating | Typical Use |
|---|---|---|---|---|---|---|
| 321 Seamless | ≥5×C | 0 | 870 | Not needed | High | Aircraft exhaust |
| 321 Welded ERW | ≥5×C | 0 | 870 | Not needed | Medium | Furnace ducting |
| 304 Seamless | 0 | 0 | 800 | Not needed | High | General service |
| 316 Seamless | 0 | 2–3 | 870 | Not needed | High | Marine chloride |
| 310S Seamless | 0 | 0 | 1150 | Not needed | High | Radiant tubes |
FAQ – 321 Stainless Steel Pipe
-
What is the maximum continuous service temperature?
870 °C in air; intermittent to 900 °C with acceptable scaling. -
Difference between 321 and 304 after welding?
321 resists sensitisation and intergranular corrosion in the 425–850 °C range; 304 does not. -
What is the price advantage of 321 stainless steel welded pipe vs seamless?
Welded is ~15 % cheaper for same size; seamless offers higher pressure rating and no weld seam. -
What sizes are available for 321 stainless steel pipe cap?
½" to 48" OD, elliptical, flat, or dished; thickness 2–40 mm manufactured in-house. -
How do I check current 321 stainless steel pipe wholesale pricing?
Login to our portal – live tonnage, coil ID, location, and certificate number updated every 30 minutes. -
Which countries do your 321 stainless steel pipe suppliers serve?
More than 70 countries including USA, Germany, India, Brazil, UAE, South Korea, and Australia. -
What certificates accompany the shipment?
EN 10204 3.1/3.2 MTC, PED 2014/68/EU, TÜV, and third-party inspection (SGS/BV) if required. -
How fast can you deliver 321 stainless steel welded pipe?
7 days production + 3–5 days ocean freight to Asian ports; 10 days to EU/US warehouses.
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Stop paying trader margins. Contact the leading 321 stainless steel pipe manufacturer today for the most competitive 321 stainless steel pipe wholesale price, immediate access to 321 stainless steel pipe cap stock, and same-day cutting of any 321 stainless steel welded pipe.