Austenitic
Broadly used, readily formed and welded; 304 and molybdenum-bearing 316 are common starting points.
Technical guide
Stainless Steel Grades Chart
Use grade names as navigation, not as a substitute for the governing product specification, chemistry, condition, dimensions and service review.
Main familiesAustenitic, ferritic, duplex
Heat treatableMartensitic and PH grades
Ordering ruleState grade plus product standard
Decision summary
Choose the family before choosing the grade
Corrosion environment, strength, fabrication, temperature, magnetism and product availability narrow the practical family and grade choices.
Ferritic
Chromium grades with useful oxidation and mild-environment performance; product form and weld demands need review.
Duplex
Mixed austenitic-ferritic structure combining higher strength with resistance to chloride stress-corrosion cracking in suitable services.
Martensitic
Heat-treatable grades selected when hardness and strength are important; corrosion resistance and weldability vary.
Precipitation hardening
Grades such as 17-4PH develop strength through solution treatment and aging; order the required condition.
Special high-alloy grades
Superaustenitic and superduplex choices require service-specific corrosion data, fabrication controls and availability review.
Reference table
Common stainless grade designation chart
These are commonly associated designations for orientation. Always verify the chemistry and product-specific standard named on the purchase order.
| Common name | UNS | Common EN number | Family | Selection cue |
|---|---|---|---|---|
| 304 | S30400 | 1.4301 | Austenitic | General-purpose fabrication and corrosion resistance |
| 304L | S30403 | 1.4307 | Austenitic | Low-carbon variant used for welded fabrication |
| 316 | S31600 | 1.4401 | Austenitic | Molybdenum-bearing grade for improved localized-corrosion resistance |
| 316L | S31603 | 1.4404 | Austenitic | Low-carbon molybdenum-bearing welded-fabrication grade |
| 321 | S32100 | 1.4541 | Austenitic | Titanium-stabilized grade for selected elevated-temperature duties |
| 430 | S43000 | 1.4016 | Ferritic | Common chromium ferritic grade for mild environments |
| 409 | S40900 | 1.4512 | Ferritic | Heat- and oxidation-oriented ferritic grade widely used in exhaust systems |
| 410 | S41000 | 1.4006 | Martensitic | Heat-treatable grade balancing strength and mild corrosion resistance |
| 420 | S42000 | 1.4021 | Martensitic | Higher-carbon heat-treatable grade for hardness |
| 2205 | S32205 / S31803 | 1.4462 | Duplex | Higher strength and chloride SCC resistance than common austenitics |
| 2507 | S32750 | 1.4410 | Superduplex | High-alloy duplex for severe chloride-containing service |
| 17-4PH / 630 | S17400 | 1.4542 | Precipitation hardening | High strength in a specified heat-treatment condition |
Cross-standard designations are not automatically interchangeable. Product scope, chemistry limits, mechanical properties, heat treatment, dimensions and certification must all match.
Need a grade comparison tied to a real service?
Send the environment, temperature, load, fabrication route, product form, standard and inspection requirements.
Working method
Verify a grade in four layers
A designation only becomes orderable when it is connected to the correct product specification and delivered condition.
Confirm the grade system
Identify UNS, ASTM type, EN number/name, JIS or another controlling designation without assuming equivalence.
Select the product standard
Plate, bar, pipe, tube, fastener and casting standards can impose different grade and property requirements.
State the delivered condition
Include solution annealed, annealed, hardened and tempered, aged, cold worked or other required condition.
Check service and fabrication
Review corrosion medium, temperature, strength, welding, forming, machining, finish and code requirements.
Limits and escalation
Do not use the chart as an equivalence certificate
Equivalent is conditional
Similar designations can differ in chemistry, testing, product scope or allowable condition.
Dual certification needs evidence
A material certificate must demonstrate compliance with every claimed designation.
Availability changes by form
A grade common in sheet may be limited in pipe, bar, wire, fittings or forgings.
Corrosion selection is service-specific
Temperature, contaminants, concentration, aeration, crevices and cleaning practice can change performance.
Visual process context
Connect the grade label to the evidence used at acceptance.
Use one image for material identification and another for the service or inspection context that controls selection.
Interactive planning aid
Choose a stainless family as a starting point
Select the dominant procurement need. The result narrows the first review; it does not approve a grade for service.
Frequently asked questions
Stainless steel grade chart FAQ
They are commonly associated designations, but compliance must be checked against the applicable standard, product form, chemistry and required properties.
304L has a lower carbon limit and is frequently selected for welded fabrication. The purchase order and certificate must identify the required grade and product specification.
No. 316 adds molybdenum and often improves localized-corrosion resistance, but suitability depends on the environment, temperature, design, fabrication and cost.
It is a precipitation-hardening stainless grade. Mechanical properties depend strongly on solution treatment and aging condition, which must be specified.
Method, sources and review
Traceable sources and review status
Industry overview of austenitic, ferritic, duplex and martensitic stainless families.
Official guide for harmonized composition limits and UNS grade designations for wrought stainless steels.
Industry-hosted reference mapping international stainless grade designations.
Official product specification for stainless plate, sheet and strip.
This chart is an orientation aid. Contract compliance comes from the cited product standard edition, purchase order and material test certificate, not from a shorthand designation alone.
Grade selection context
Match the grade name to the service environment and product form.
A grades chart is a routing aid. Confirm the exact designation, standard, product form, corrosion exposure and certification requirements before purchasing.
- Designation system
- Service exposure
- Certificate basis