Grade dossier
308 Stainless Steel: Wrought Grade and Welding-Alloy Distinction
A 19-21% chromium, 10-12% nickel wrought stainless grade that must be kept distinct from AWS ER308 and E308 welding-consumable classifications.
Identity before substitution
Define the grade, product and condition together
A familiar grade name is not a complete purchase specification. Product form, controlling standard, dimensions, condition, finish, certification and service environment determine whether the delivered material is suitable.
Composition control
UNS S30800 wrought-grade chemistry
Limits are not heat analysis targets
This table is for wrought UNS S30800. It is not the acceptance table for ER308 wire, E308 electrodes or deposited weld metal. Welding consumables must be ordered to the applicable AWS/SFA classification.
| C | 0.08 max |
|---|---|
| Mn | 2.00 max |
| Si | 1.00 max |
| P | 0.045 max |
| S | 0.030 max |
| Cr | 19.00-21.00 |
| Ni | 10.00-12.00 |
Properties with context
Minimums, typical indicators and delivered condition
Annealed wrought-product reference values
| Tensile strength | 515 MPa min reference |
|---|---|
| 0.2% yield strength | 205 MPa min reference |
| Elongation | 40% min reference |
| Hardness | 88 HRB max reference |
Selection indicators
| Density | about 8.0 g/cm3 |
|---|---|
| Primary caution | Wrought 308 and ER308 are not interchangeable specifications |
| Welding role | 308 chemistry is commonly associated with 18-8 filler-metal design |
| Availability | Verify product form and mill availability before design freeze |
Values depend on product form, thickness, test orientation, condition and governing edition. Use the mill test certificate and the purchase specification for acceptance, not a web table alone.
Selection boundary
Where 308 belongs and where to escalate
Grade selection is an environmental decision, not a popularity contest. Review the complete medium, temperature, geometry, fabrication, cleaning and inspection requirements.
Good reasons to evaluate it
Projects explicitly requiring wrought UNS S30800
Special bar, wire or forged-product orders under a named standard
Technical comparisons with 304 and 308 filler chemistry
Applications with certificate-level identity control
Reasons to stop and review
Ordering ER308 welding wire as UNS S30800 wrought stock
Assuming a 308 page defines deposited weld-metal properties
Substituting 304 or 305 by number similarity
Writing an RFQ without product form and governing standard
Fabrication route
Protect properties through cutting, forming and welding
Separate base-metal specification from filler-metal classification.
For welding, select ER308, ER308L or another consumable from base metal, dilution and service.
Request certificates against the exact standard named on the order.
Confirm wrought-product availability before committing drawings.
Supply definition
Product form changes the applicable requirements
Do not send an RFQ that names only the grade. State form, governing standard, dimensions, tolerances, finish, edge or end condition, quantity, certification and inspection.
Wrought bar, wire or forgings under product-specific standards
Historical plate, sheet and strip references require edition review
ER308/ER308L wire and rods under AWS A5.9 are separate products
E308 covered electrodes under AWS A5.4 are separate products
Certificate checkpoint
Request heat identity, chemical analysis, mechanical results and compliance to the exact product specification. Add PMI, corrosion testing or supplementary examination only when the application requires it.
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Interactive selection check
Test 308 against the controlling question
Procurement FAQ
Questions to close before placing the order
Is 308 stainless steel magnetic?
Magnetic response depends on microstructure and delivered condition.
Can 308 replace another grade?
Only after checking the governing standard, composition, mechanical properties, corrosion exposure, fabrication route and certification. A commercial name is not a substitution approval.
Does the table apply to every product form?
No. Wrought UNS S30800 properties, ER308 wire requirements and E308 deposited-weld-metal tests come from different specifications.
What should a 308 RFQ include?
Product form, standard and edition, UNS or EN designation, dimensions, tolerances, finish, quantity, service, fabrication, certificate and inspection requirements.
Sources, scope and RFQ
Use traceable grade data, then specify the actual product
ASTM A959 harmonized composition for wrought UNS S30800
Carpenter and industry wrought 308 grade references
AWS A5.9/SFA-5.9 ER308 welding-consumable classification
Lincoln Electric ER308 wire technical specification