Welded Stainless Steel Pipe & Tube
JCNMetal — Precision Welded Stainless Steel Pipe & Tube Manufacturer
JCNMetal Welded Stainless Steel Pipes
At JCNMetal, our welded stainless steel pipes are made for the realities of industry — steady welds, clean internal surfaces, and reliable performance where heat and pressure don’t forgive mistakes.
Each pipe is welded and finished to maintain flow integrity and corrosion resistance across long service cycles.
Grades available: 304, 304L, 316L, 321, 347, 310S, 904L – trusted in chemical lines, boiler systems, structural fabrication, and marine pipelines.
Why Choose Welded Stainless Steel Pipes
JCNMetal welded stainless steel pipes combine precision forming with automatic welding to ensure uniform seams, smooth internal surfaces, and strong corrosion resistance.
Each pipe is tested for weld integrity, dimension accuracy, and surface finish to guarantee consistent performance in flow systems and structural applications.
- Smooth welds ensure clean flow and stable pressure
- Reliable strength and corrosion resistance in service
- Cost-efficient option for large-scale or custom projects
Stainless Steel Pipe Materials Overview
| Grade (AISI) | JIS Equivalent | EN / DIN | GB |
|---|---|---|---|
| 304 | SUS304 | 1.4301 | 06Cr19Ni10 |
| 304L | SUS304L | 1.4306 | 00Cr19Ni10 |
| 304H | SUS304H | 1.4948 | 07Cr19Ni10 |
| 309S | SUS309S | 1.4833 | 06Cr23Ni13 |
| 310S | SUS310S | 1.4845 | 06Cr25Ni20 |
| 316 | SUS316 | 1.4401 | 06Cr17Ni12Mo2 |
| 316L | SUS316L | 1.4404 | 00Cr17Ni14Mo2 |
| 316H | SUS316H | 1.4436 | – |
| 316Ti | SUS316Ti | 1.4571 | 06Cr17Ni12Mo2Ti |
| 316LN | SUS316LN | 1.4429 | – |
| 317L | SUS317L | 1.4438 | 00Cr19Ni13Mo3 |
| 321 | SUS321 | 1.4541 | 06Cr18Ni11Ti |
| 321H | SUS321H | 1.4541 | – |
| 347 | SUS347 | 1.4550 | 06Cr18Ni11Nb |
| 347H | SUS347H | 1.4912 | – |
| 904L | SUS904L | 1.4539 | 00Cr20Ni25Mo4.5Cu |
| 253MA | SUS253MA | 1.4835 | 06Cr25Ni14Si2 |
| 254SMo | SUS254SMo | 1.4547 | 00Cr20Ni18Mo6CuN |
| Grade (AISI) | JIS Equivalent | EN / DIN | GB |
|---|---|---|---|
| 409 | SUS409 | 1.4512 | 11CrTi |
| 410L | SUS410L | 1.4003 | 11Cr17 |
| 430 | SUS430 | 1.4016 | 12Cr17 |
| 434 | SUS434 | 1.4113 | 10Cr17Mo2 |
| 436 | SUS436 | 1.4536 | 12Cr17Ti |
| 439 | SUS430LX | 1.4510 | 17CrTi |
| 444 | SUS444 | 1.4521 | 00Cr18Mo2 |
| Grade (AISI) | JIS Equivalent | EN / DIN | GB |
|---|---|---|---|
| 410 | SUS410 | 1.4006 | 12Cr13 |
| 410S | SUS410S | 1.4000 | 06Cr13 |
| 420 | SUS420J1 / J2 | 1.4021 / 1.4028 | 12Cr13 / 20Cr13 |
| 431 | SUS431 | 1.4057 | 15Cr16Ni2Mo |
| 440A / 440B / 440C | SUS440A–C | 1.4112–1.4125 | 7Cr17 / 9Cr18 |
| 420F | SUS420F | 1.4029 | 12Cr13S |
| 17-4PH | SUS630 | 1.4542 | 0Cr17Ni4Cu4Nb |
| 17-7PH | SUS631 | 1.4568 | 0Cr17Ni7Al |
| 15-5PH | S15500 | 1.4542 | 0Cr15Ni7Mo2Al |
| Grade (AISI) | JIS Equivalent | EN / DIN | GB |
|---|---|---|---|
| S31803 | F51 / SUS329J3L | 1.4462 | 00Cr22Ni5Mo3N |
| S32205 | 2205 / SUS329J3L | 1.4462 | 00Cr22Ni5Mo3N |
| S32750 | 2507 / F53 | 1.4410 | 00Cr25Ni7Mo4N |
| S32760 | F55 | 1.4501 | 00Cr25Ni7Mo4WCuN |
| S32550 | 255 / SUS329J4L | 1.4507 | 00Cr25Ni7Mo3CuN |
Common Challenges and JCNMetal Solutions
Our welded stainless steel pipes are designed to overcome the common issues found in conventional welding and fabrication
— ensuring integrity, uniformity, and long-term reliability in every application.
| Industry Issue | JCNMetal Solution |
|---|---|
| Uneven weld seams cause leaks or weak joints under pressure. | We use automatic TIG and plasma welding systems with real-time seam tracking to ensure continuous, uniform weld penetration and consistent mechanical strength. |
| Surface oxidation and discoloration after welding reduce corrosion resistance and appearance quality. | Weld seams and heat-affected zones are pickled and passivated under controlled conditions, restoring full corrosion resistance and achieving a clean, metallic finish. |
| Internal weld beads create turbulence or bacterial buildup in process piping. | Optional internal bead removal and mechanical polishing produce smooth inner surfaces (Ra < 0.8 μm), ideal for flow and sanitary applications. |
| Dimensional deviation between welded sections affects fit-up or assembly. | Automatic forming and inline sizing ensure stable diameter and roundness tolerance within ±0.3 mm. |
| Residual stress from welding leads to distortion or cracking during service. | Post-weld heat treatment (PWHT) relieves internal stress and refines grain structure, improving long-term dimensional stability. |
Where Our Welded Pipe Are Used

Process Piping
Used in fluid transport systems requiring corrosion resistance.

Frame Parts
For load-bearing frameworks and industrial supports.

Heat Exchangers
Applied in boilers, condensers, and thermal systems.

Food Equipment
For hygienic tubing in clean processing environments.

Marine Systems
Used in ship piping and offshore structural lines.

Power Plant
For steam lines and high-temperature service piping.

Chemical Plants
Used in reactors, tanks, and acid-resistant pipelines.

Water Treatment
Applied in desalination, sewage, and filtration systems.
Welded Stainless Steel Pipe Range
| Forming Type | Outer Diameter (mm) | Wall Thickness (mm) | Available Finishes |
|---|---|---|---|
| Coil Welded Tubes | 6 – 630 | 0.3 – 6.0 | 2B, BA, No.4, HL, Polished |
| Plate Welded Pipes | 530 – 2800 | 3.0 – 45.0 | Pickled, Polished, Custom Finish |
Delivery State: Annealed & Pickled / Polished
Surface Protection: PVC / PE Film, End Caps Available
Standards: ASTM A312 / A358 / A249 / A269 / GB/T 12771
Tolerance
ASTM A269 – Permissible Variations
| Group | Size, Outside Diameter (in.) | Permissible Variations in Outside Diameter (in.) (mm) | Permissible Variations in Wall Thickness (%) | Permissible Variations in Cut Length (in.) (mm) – Over | Under | Thin Walled Tubes |
|---|---|---|---|---|---|---|
| 1 | Up to ½ | ±0.005 (0.13) | ±15 | ⅛ (3.2) | 0 | less than 0.065 in. (1.65 mm) nominal |
| 2 | ½ to 1½, excl | ±0.005 (0.13) | ±10 | ⅛ (3.2) | 0 | less than 0.095 in. (2.41 mm) nominal |
| 3 | 1½ to 3½, excl | ±0.010 (0.25) | ±10 | 3⁄16 (4.8) | 0 | less than 0.150 in. (3.81 mm) nominal |
| 4 | 3½ to 5½, excl | ±0.015 (0.38) | ±10 | 3⁄16 (4.8) | 0 | less than 0.150 in. (3.81 mm) nominal |
| 5 | 5½ to 8, excl | ±0.030 (0.76) | ±10 | 3⁄16 (4.8) | 0 | less than 0.150 in. (3.81 mm) nominal |
| 6 | 8 to 12, excl | ±0.040 (1.01) | ±10 | 3⁄16 (4.8) | 0 | less than 0.200 in. (5.08 mm) nominal |
| 7 | 12 to 14, excl | ±0.050 (1.26) | ±10 | 3⁄16 (4.8) | 0 | less than 0.220 in. (5.59 mm) nominal |
ASTM A312 – Tolerances (% from Nominal)
| NPS Designator | Tolerance Over (%) | Tolerance Under (%) |
|---|---|---|
| ½ to 2½ incl., all t/D ratios | 20 | 12.5 |
| 3 to 18 incl., t/D up to 5% incl. | 22.5 | 12.5 |
| 3 to 18 incl., t/D > 5% | 15 | 12.5 |
| 20 and larger, welded, all t/D ratios | 17.5 | 12.5 |
| 20 and larger, seamless, t/D up to 5% incl. | 22.5 | 12.5 |
| 20 and larger, seamless, t/D > 5% | 15 | 12.5 |
ASTM A554 – Tolerances
| OD Size (in.) (mm) | Wall Thickness (in.) | Wall Thickness (mm) | OD Tolerance (in.) | OD Tolerance (mm) |
|---|---|---|---|---|
| Under ½ (12.7) | 0.020 to 0.049 | 0.51 to 1.24 | 0.004 | 0.10 |
| ½ to 1 (12.7 to 25.4) | 0.020 to 0.065 | 0.51 to 1.65 | 0.005 | 0.13 |
| ½ to 1 (12.7 to 25.4) | 0.065 to 0.134 | 1.65 to 3.40 | 0.008 | 0.20 |
| Over 1 to 1½ (25.4 to 38.1) incl | 0.025 to 0.065 | 0.64 to 1.65 | 0.010 | 0.25 |
| Over 1½ to 2 (38.1 to 50.8) incl | 0.025 to 0.083 | 0.64 to 2.11 | 0.011 | 0.28 |
| Over 2 to 2½ (50.8 to 63.5) incl | 0.032 to 0.109 | 0.81 to 4.19 | 0.014 | 0.36 |
| Over 2½ to 3 (63.5 to 88.9) incl | 0.032 to 0.165 | 0.81 to 4.19 | 0.018 | 0.46 |
| Over 3 to 3½ (88.9 to 127.0) incl | 0.035 to 0.165 | 0.89 to 4.19 | 0.021 | 0.53 |
| Over 5 to 7½ (127.0 to 190.5) incl | 0.049 to 0.250 | 1.24 to 6.35 | 0.035 | 0.89 |
| Over 7½ to 16 (190.5 to 406.4) incl | over 0.250 | over 6.35 | 0.043 | 1.09 |
Quality Control You Can Trust
- Automatic seam welding inspection ensures full weld penetration and consistent bead formation across every pipe.
- X-ray and hydrostatic testing verify internal weld integrity and pressure resistance before shipment.
- Post-weld heat treatment (PWHT) relieves stress and restores corrosion resistance in heat-affected zones.
- Surface pickling and passivation remove oxides and restore a clean, metallic finish for sanitary or visible use.
- Dimensional and roundness checks confirm precise tolerances for easy fit-up and reliable assembly.
Surface Options
- Silver Bright (Hot Rolled): natural metallic sheen achieved from controlled hot rolling and finishing, providing a clean industrial appearance.
- Polished 320#: medium-grain polish with visible texture, suitable for general decorative or architectural use.
- Polished 400#: fine-grain polish offering smoother reflection and improved surface uniformity.
- Polished 600#: ultra-fine finish with semi-mirror brightness, ideal for clean or exposed piping.
- Mirror Finish: high-gloss, fully reflective surface for premium aesthetic or sanitary pipe applications.
Both <strong>Hot Rolled</strong> and <strong>Cold Rolled</strong> welded pipes are available in Silver Bright and Polished finishes, delivering excellent appearance and surface consistency for industrial and decorative use.
Packaging and Delivery
- Bundled with steel straps and wrapped in thick woven plastic bags to prevent scratches, dust, and moisture during shipment.
- Optional wooden cases available for pipes requiring extra protection against stress or rough handling — especially recommended for air transport.
- Each bundle of welded stainless steel pipes clearly labeled with size, grade, surface finish, and heat number for traceability.
- Customized packaging can be provided according to customer requirements for special pipe types or export standards.
- Standard shipping arranged by sea under FOB, CFR, or CIF terms; air shipment available upon request for urgent orders.
- All welded stainless steel pipes packed and delivered according to international standards to ensure safe arrival and clean surface condition.
Why JCN Metal
- JCNMetal with in-house forming, welding, and polishing lines dedicated to precision welded stainless steel pipe production.
- ISO 9001 certified manufacturing process with 100% weld inspection and dimensional control.
- Advanced TIG, plasma, and laser welding systems ensure uniform seams and reliable mechanical strength.
- Over 60 export countries supplied with stable quality and consistent delivery performance.
- Custom diameter, thickness, and surface finish options available to meet project-specific requirements.
- Traceable MTC and final inspection reports provided for every batch to guarantee transparency and quality assurance.