Product Name: Polished Seamless Tube
Material: Stainless Steel 321
Standard: ASTM A269 / ASME SA269, ASTM A213 / ASME SA213, EN 10216-5
Outer Diameter (OD): 1/4" – 2"
Surface Finish: Polished (Internal & External)
Length: Fixed Length (6m) or Cut-to-Length
321BA Tube Application
With its excellent high-temperature stability, TP321 seamless tube is widely used in various harsh thermal environments. Typical applications include exhaust manifolds and gathering rings for aircraft and aerospace, superheater and reheater tubes for boilers and pressure vessels, components for industrial furnaces, as well as chemical equipment and heat exchanger systems for processing corrosive media at high temperatures. In these critical applications, TP321 ensures the structural integrity of the equipment at high temperatures and the reliability of long-term operation.
Bright Annealing Process
SMLSCO TP321 seamless tube is heat-treated using advanced Bright Annealed technology. Throughout the process, the tubes are heated and cooled in a controlled atmosphere furnace filled with inert or reducing gases. This can effectively prevent oxidation of the tube surface at high temperatures, forming a smooth surface that is bright, clean, and free of oxidation skin. This process not only optimizes the mechanical properties and corrosion resistance of the material, but also provides an excellent surface foundation for subsequent polishing treatments and cleanliness requirements.
Chemical Composition of 321 Stainless Steel
| Material | Chemical Composition % Max ASTM A269 |
| C | Mn | P | S | Si | Cr | Ni | Mo | Nb | Ti |
| TP304 | 0.08 | 2 | 0.045 | 0.03 | 1 | 18.0-20.0 | 8.0-11.0 | - | - | - |
| TP304L | 0.035 | 2 | 0.045 | 0.03 | 1 | 18.0-20.0 | 8.0-12.0 | - | - | - |
| TP316 | 0.08 | 2 | 0.045 | 0.03 | 1 | 16.0-18.0 | 10.0-14.0 | 2.00-3.00 | - | - |
| TP316L | 0.035 | 2 | 0.045 | 0.03 | 1 | 16.0-18.0 | 10.0-15.0 | 2.00-3.00 | - | - |
| TP321 | 0.08 | 2 | 0.045 | 0.03 | 1 | 17.0-19.0 | 9.0-12.0 | - | - | 5C -0.70 |
| TP347 | 0.08 | 2 | 0.045 | 0.03 | 1 | 17.0-19.0 | 9.0-12.0 | - | 10C -1.10 | - |
Physical Property of 321 Stainless Steel
| Steel grade | Physical Property |
| Y.S | T.S | EL. | HRB |
| 304 | ≥205 | ≥515-1035 | ≥40 | ≤92 |
| 304L | ≥205 | ≥520 | ≥40 | ≤90 |
| 316 | ≥620 | ≥310 | ≥30 | ≤95 |
| 316L | ≥480 | ≥177 | ≥40 | ≤90 |
| 321 | ≥205 | ≥515 | ≥40 | ≤95 |
| 347 | ≥205 | ≥515 | ≥40 | ≤92 |
Material Properties of TP321
The core advantage of 321 stainless steel lies in its excellent resistance to intergranular corrosion. By adding stabilizing element titanium (Ti), it can effectively suppress the formation of chromium carbide at high temperatures (425-850 ° C) or in the welding heat affected zone, thereby avoiding the deterioration of material properties. This characteristic makes it perform much better than 304 or 316 stainless steel in working conditions that require repeated high-temperature cycles or cannot undergo post weld solution treatment. It is a reliable material designed specifically for high-temperature environments and has good creep and stress fracture properties.
Core Advantages of SMLSCO
SMLSCO is not only an inventory expert for conventional stainless steel grades, but also relies on a strong supply chain network and 19 years of industry experience to provide you with reliable supply of steel such as TP321. We understand your strict requirements for the performance and quality of high-temperature alloys. Through our mature quality control system, we ensure that every TP321 tube produced meets international standards. Choosing us means you have chosen stable quality, competitive prices, and reliable delivery guarantees.
