347 Stainless Steel Coil Supplier for High-Temperature Fabrication and Welded Equipment

Regular 304 and other common austenitic stainless steels perform poorly if your parts need repeated welding or long-term service under continuous high heat. We add niobium as a stabilizing element to 347 grade, which restrains chromium carbide precipitation during heating. Even after multiple welding passes, the material can retain reliable anti-corrosion performance without extra treatment.

This coil material fits fabricators making pressure vessels, heat exchangers, industrial exhaust piping and refinery hardware perfectly. It balances stable weldability and consistent mechanical performance under sustained high operating temperatures, solving common sensitization issues seen with standard stainless grades.

Products Description

Item

Details

Standard

ASTM A240 / ASTM A480

Grade

347 / UNS S34700

Thickness

0.3 mm – 20 mm

Width

20 mm – 2000 mm

Surface Finish

No.1, 2B, BA, No.4

Lead Time

7–15 working days for regular in-stock sizes18–25 working days for customized surface / slitting orders

Custom Processing Service

Slitting to narrow widths, cut-to-length sheets, leveling, pre-treatment for laser cutting & forming

Payment Terms

T/T, L/C

Trade Terms

FOB, CFR, CIF

Property	Value
Chromium (Cr)	17.0 – 19.0%
Nickel (Ni)	9.0 – 13.0%
Carbon (C)	≤0.08%
Tensile Strength	≥515 MPa
Yield Strength	≥205 MPa
Elongation	≥40%

Why 347 Coil Is Selected for High-Temperature Projects

Improved intergranular corrosion resistance post welding

Niobium alloying stops chromium carbide segregation when welding. Unlike standard stainless steel, welded heat-affected zones won't lose corrosion resistance, making it the top pick for permanently welded high-temperature components.

Stable performance under long-duration high heat

This grade is widely used for equipment running steadily between 500°C and 800°C. Ordinary 304 stainless steel will suffer sensitization and weakened anti-corrosion ability after long exposure in this temperature band.

Cuts down post-weld heat treatment steps

Most finished components made with 347 do not require solution annealing after welding. It shortens your whole production workflow and effectively lowers overall manufacturing costs.

Flexible pre-processing to reduce your workshop workload

We offer full coil machining before shipment: narrow slitting, custom-sized plate cutting, pre-flattening and forming preparation for laser cutting. Customers receive semi-finished material ready for direct fabrication to save internal machining hours.