347 Stainless Steel Bar

UNS S34700 (Grade 347)

347 stainless steel bar, also known as UNS S34700 and Grade 347, is an austenitic stainless steel made of .08% maximum carbon, 17% to 19% chromium, 2% maximum manganese, 9% to 13% nickel, 1% maximum silicon, traces of phosphorus and sulfur, 1% minimum to 10% maximum columbium and tantalum with the balance of iron. Grade 347 is advantageous for high temperature service because of its good mechanical properties; it also has excellent resistance to intergranular corrosion following exposure to temperatures in the chromium carbide precipitation range from 800° to 1500° F. It is similar to Grade 321 with respect to intergranular corrosion which is achieved through the use of columbium as a stabilizing element to maximize this feature. Grade 347 can not be hardened through heat treating, but elevated properties may be obtained through cold reduction.

Industries that use 347 include:

  • Aerospace
  • Valve

Products partially or completely constructed of 347 include:

  • Aircraft collector rings
  • Chemical production equipment
  • Engine parts
  • Exhaust manifolds
  • High temperature gaskets and expansion joints
  • Rocket engine parts
Stocking Diameters ½” to 24”
Material Lengths Up to 12’
Bar Specifications
Uns Type Ams Astm Federal Characteristics
S34700 347 5646
5654
A-276
A-314
A-479
QQ-S-763 347 is overall superior to 321, but with similar characteristics. 347 is stabilized by cobalt and tantalum, easily welded, resists intergranular corrosion.
Chemistry Analysis
C MN P S SI CR NI MO CU OTHER M/NM
.08 2. .045 .03 1. 17. – 19. 9. – 13. .5 .5 Cb + Ta = 10xC Max. NM

The information above is not warranted, guaranteed, or for design purposes.

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