347 Stainless Steel Bar (AMS 5646)
Arch Metals supplies 347 stainless steel bar from Dallas, Texas, to aerospace, energy and process-equipment customers across Texas and the surrounding states. 347 is an austenitic stainless steel stabilized with niobium (columbium), which protects it from intergranular corrosion after high-temperature exposure or welding. We supply annealed 347 bar to AMS 5646 and ASTM A276/A479 with certified material and saw cutting to length. Request a quote and we’ll confirm sizes and availability.
347 Stainless Steel Forms
- Round bar, annealed
- Hex and flat bar on request
- Plate and sheet on request
Size availability changes with mill supply. Send us your sizes through our quote request form and we’ll confirm stock, lead time and pricing.
347 Stainless Steel Condition and Specifications
- Annealed bar (AMS 5646, ASTM A276, ASTM A479): solution annealed for corrosion resistance and ductility. Like other austenitic grades, 347 is not hardenable by heat treatment.
- Equivalent designations (UNS S34700): also called Type 347 or columbium-stabilized 18-8 stainless.
Not sure which condition or specification your drawing calls for? Send us the print requirements and we’ll match the material.
Typical Properties of Annealed 347 Stainless Steel
- Ultimate tensile strength: about 95 ksi (655 MPa)
- Yield strength: about 35 ksi (240 MPa)
- Elongation: about 45%
- Hardness: about 85 HRB
- Density: 0.288 lb/in³ (7.96 g/cm³)
- Chemistry: about 18% chromium and 11% nickel, stabilized with niobium
These are typical values for annealed bar. Guaranteed minimums vary by specification, condition and size, so check the governing spec or your mill cert for design values.
Why Engineers Choose 347 Stainless Steel
Niobium forms very stable carbides, so 347 resists sensitization during welding and long service at 800°F to 1500°F. It also has slightly better creep strength than 321 stainless steel at high temperature, and it is the usual choice when parts are welded and can’t be annealed afterward. For general room-temperature parts, 304 stainless costs less. Common uses for 347 include:
- Aircraft and jet engine exhaust components
- High-temperature welded assemblies
- Refinery and chemical process equipment
- Steam lines and boiler components
347 Stainless Steel FAQs
What is the difference between 347 and 321 stainless steel?
Both are stabilized austenitic grades. 347 uses niobium and 321 uses titanium. 347 holds up slightly better in very high-temperature and welded service; 321 is more widely stocked in bar and sheet.
Is 347 stainless steel weldable?
Yes. 347 welds well, and its stabilization keeps the heat-affected zone from becoming sensitized, so post-weld annealing is usually not needed for corrosion resistance.
Is 347 stainless steel magnetic?
Annealed 347 is essentially non-magnetic. Cold working can make it slightly magnetic.
Cut-to-Size 347 Stainless Steel With Delivery Across Texas
We ship 347 stainless steel throughout Texas, Oklahoma, Louisiana, New Mexico and Arizona, and we saw bar and plate to the size you need. See our processing services for cutting options, or browse all the metals we supply. We also supply 321 stainless and 316 stainless steel.
To get pricing, send us the grade, condition, form, size, length and quantity through our quote request form, or call (888) 444-6061.