Grade dossier
316L Stainless Steel for Welded and Corrosive Service
The low-carbon 316 variant widely specified for welded equipment requiring molybdenum-enhanced localized-corrosion resistance and controlled documentation.
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
ASTM A240/A240M flat-product chemistry
Limits are not heat analysis targets
The table summarizes grade limits commonly used for plate, sheet and strip. Pipe, tube, bar, forgings and cast products can be governed by different specifications. Always place the product standard and edition on the purchase order.
| C | 0.030 max |
|---|---|
| Mn | 2.00 max |
| Si | 0.75 max |
| P | 0.045 max |
| S | 0.030 max |
| Cr | 16.00-18.00 |
| Ni | 10.00-14.00 |
| Mo | 2.00-3.00 |
| N | 0.10 max |
Properties with context
Minimums, typical indicators and delivered condition
Specified annealed flat-product values
| Tensile strength | 485 MPa min |
|---|---|
| 0.2% yield strength | 170 MPa min |
| Elongation | 40% min |
| Hardness | 95 HRB max |
Selection indicators
| Density | about 8.0 g/cm3 |
|---|---|
| PRE indicator | about 24-26; not a service limit |
| Welded fabrication | Low carbon reduces sensitization risk |
| Magnetic response | Normally low when annealed |
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 316L 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
Welded process equipment
Food, pharmaceutical and laboratory systems after hygienic review
Chemical handling after corrosion review
Coastal hardware with appropriate detailing and maintenance
Reasons to stop and review
Direct seawater assurance without site data
Crevices, deposits or stagnant chlorides without review
Using the L suffix as a substitute for procedure control
Assuming all 316L product forms share one property table
Fabrication route
Protect properties through cutting, forming and welding
Good weldability does not remove the need for procedure qualification.
Control heat input, shielding, filler and interpass condition.
Remove heat tint and restore a clean surface where corrosion performance matters.
Specify whether dual-certified 316/316L is acceptable.
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.
Sheet, coil and plate
Welded and seamless tube under separate standards
Bar and fittings
Fabricated hygienic and process equipment
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.
Interactive selection check
Test 316L against the controlling question
Procurement FAQ
Questions to close before placing the order
Is 316L stainless steel magnetic?
Magnetic response depends on microstructure and delivered condition.
Can 316L 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 pipe, tube and bar?
Not automatically. The values shown use flat-product requirements as a reference. Other forms can use different product standards, dimensions and tests.
What should a 316L 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 A240/A240M flat-rolled composition and mechanical requirements
Atlas Grade Datasheets: 316, 316L and 316H
Outokumpu Supra 316L/4404 data
worldstainless corrosion and fabrication guidance