Stainless Steel 443 welded pipes and tubes are made to ASTM A268 Grade TP443 (UNS S44300) and offer a practical combination of corrosion resistance, strength and low nickel content. This ferritic stainless steel contains 18% to 23% chromium and 0.90% to 1.25% copper, with the copper addition helping improve resistance in certain reducing acid environments. The grade is magnetic and provides a minimum yield strength of 275 MPa. Amardeep Steel supplies SS 443 welded pipes and tubes with EN 10204 3.1 mill test certificates and full heat traceability. For heavier wall requirements, see our SS 443 seamless pipes and tubes, or browse our SS welded pipes and tubes. FOLD 2
What Are Stainless Steel 443 Welded Pipes and Tubes?
ASTM A268 covers seamless and welded ferritic and martensitic stainless steel tubing for general service, and TP443 is one of its listed grades. Welded TP443 is formed from strip, welded along a longitudinal seam without filler, and annealed. The standard calls for flattening and flange tests on welded tube, and a hydrostatic or electric test on every length.
Two Grades Called "443"
The traditional Type 443 is UNS S44300, the grade in ASTM A268. A newer ferritic steel also sold as "443" (UNS S44330, JIS SUS443J1) has about 21% chromium, low carbon, copper and titanium or niobium stabilization, and is mainly sold as sheet. This page covers TP443 (S44300). If your drawing names S44330, say so with your enquiry.
SS 443 Welded Tube Specifications
Parameter | Details |
|---|---|
Grade | Stainless Steel 443 (TP443) |
UNS | S44300 |
Standard | ASTM A268 / ASME SA268 |
Type | Welded without filler (TIG or ERW), longitudinal seam |
Outside Diameter | Small and medium bore tube to ASTM A268 tolerances |
Length | Random, fixed and cut lengths |
Ends | Plain end and bevelled end |
Heat Treatment | Annealed |
Test Certificate | EN 10204 3.1, with 3.2 available on request |
SS 443 Chemical Composition
Element | Content (%) |
|---|---|
Carbon (C) | 0.20 max |
Chromium (Cr) | 18.0 to 23.0 |
Copper (Cu) | 0.90 to 1.25 |
Nickel (Ni) | 0.75 max |
Manganese (Mn) | 1.00 max |
Silicon (Si) | 1.00 max |
Phosphorus (P) | 0.040 max |
Sulfur (S) | 0.030 max |
SS 443 Mechanical Properties
Property | Value |
|---|---|
Tensile Strength, min | 485 MPa (70 ksi) |
Yield Strength (0.2% offset), min | 275 MPa (40 ksi) |
Elongation in 50 mm, min | 20% |
Hardness, max | 207 HBW / 95 HRB |
Values are the ASTM A268 minimums for TP443. Actual results for each heat are stated on the mill certificate.
SS 430 vs 439 vs 443 Welded Tube
Property | TP430 | TP439 | TP443 |
|---|---|---|---|
Chromium | 16 to 18% | 17 to 19% | 18 to 23% |
Copper | Not specified | Not specified | 0.90 to 1.25% |
Stabilization | None | Titanium | None |
Carbon, max | 0.12% | 0.07% | 0.20% |
For a titanium stabilized welded option, see our SS 439 tubes. For scaling resistance without copper, see our SS 442 welded pipes and tubes.
Applications of SS 443 Welded Pipes and Tubes
- Chemical process tubing in mildly reducing media
- Heat exchanger tubes; see our heat exchanger tubes
- Food processing and kitchen equipment tubing
- Oven, dryer and furnace parts
Testing and Documentation
Every order of SS 443 welded tube goes through the checks below at our testing facility or approved third party labs.
- Chemical analysis and PMI
- Tension test
- Flattening, reverse flattening and flange tests on the weld
- Hardness test
- Hydrostatic or eddy current test
- Visual and dimensional inspection
Mill test certificates are issued to EN 10204 3.1, with 3.2 available on request. You can view our approvals on the certificates page.
Packing and Marking
Each length is marked with ASTM A268, TP443, size, heat number and manufacturer name. Ends are capped and tubes are packed in bundles or wooden boxes for export. Read more about our packing and despatch process.
Request a Quote for Stainless Steel 443 Welded Pipes & Tubes
Send us the OD, wall thickness, length, quantity and whether your drawing calls for S44300 or S44330, and our team will reply with price and delivery. Use the enquiry form or reach us through the contact page.
Frequently Asked Questions
What is SS 443 welded tube?
It is ASTM A268 TP443 (UNS S44300) tube, a ferritic stainless steel with 18% to 23% chromium and 0.90% to 1.25% copper, welded along a longitudinal seam and annealed.
What are the mechanical properties of TP443?
ASTM A268 sets TP443 at 485 MPa minimum tensile strength, 275 MPa minimum yield strength, 20% minimum elongation and 207 HBW maximum hardness.
What is the difference between UNS S44300 and S44330?
S44300 is the traditional Type 443 in ASTM A268, with up to 0.20% carbon and copper. S44330 is a newer 21% chromium grade with low carbon, copper and titanium or niobium stabilization, sold mainly as sheet.
Is SS 443 welded tube magnetic?
Yes. TP443 is a ferritic stainless steel and is magnetic.
