Stainless steel / UNS S31700
317 raises molybdenum to 3–4% and chromium to 18–20%, giving better pitting and crevice resistance than 316 in acidic and chloride-bearing process streams.
- UNS S31700
- Spec ASTM A240
- Density 7.98 g/cm³
Also known as / equivalents
| System | Designation |
|---|---|
| UNS | S31700 |
| JIS | SUS317 |
| Also known as | AISI 317 |
Chemical composition
| Element | Min % | Max % |
|---|---|---|
| C | — | 0.08 |
| Mn | — | 2.00 |
| P | — | 0.045 |
| S | — | 0.030 |
| Si | — | 0.75 |
| Cr | 18.0 | 20.0 |
| Ni | 11.0 | 15.0 |
| Mo | 3.0 | 4.0 |
| N | — | 0.10 |
| Fe | Bal. | — |
Mechanical properties
| Property | Value |
|---|---|
| Tensile strength (min) | 515 MPa (74.7 ksi) |
| Yield strength, 0.2% offset (min) | 205 MPa (29.7 ksi) |
| Elongation in 50 mm (min) | 35 % |
| Hardness | 217 HB max |
Physical properties
| Property | Metric | Imperial |
|---|---|---|
| Density | 7.98 g/cm³ | 0.288 lb/in³ |
| Magnetic response | Non-magnetic when annealed; may become slightly magnetic after cold work | — |
Available forms & specifications
| Form | Specification | Size range |
|---|---|---|
| Sheets, plates & coils | ASTM A240 / ASME SA240 | 0.3 mm – 6 mm |
| Seamless & welded pipe | ASTM A312 / ASME SA312 | 1/8" – 24" NB |
| Tubes | ASTM A213, A249, A269 | 1/8" – 24" NB |
| Bars & rods | ASTM A276, A479 | 3 mm – 500 mm |
| Flanges & forgings | ASTM A182 / ASME SA182 | 1/2" – 48" NB (larger on request) |
| Buttweld fittings | ASTM A403 / ASME SA403 | 1/2" – 48" NB |
| Fasteners | ASTM A193 / A194, F593 / F594 | M3 – M56 |
Corrosion & temperature resistance
Corrosion resistance rises with chromium, molybdenum and nitrogen: 304 handles general atmospheric and food-contact service, 316/317 add resistance to chlorides and pitting, 904L handles strong reducing acids, and stabilised 321/347 resist intergranular attack after welding or high-temperature exposure.
Applications
SS 317: Pulp and paper, FGD, chemical processing. Process piping, tanks and vessels, heat exchangers, food, dairy and pharmaceutical equipment, architectural work and general engineering.
SS 317 vs SS 317L
| SS 317 | SS 317L | |
|---|---|---|
| UNS | S31700 | S31703 |
| Key property | Higher Mo than 316 | Low-carbon 317 for welding |
| Typical use | Pulp and paper, FGD, chemical processing | Scrubbers, condensers, chemical plant |
| Cr (wt %) | 18.0–20.0 | 18.0–20.0 |
| Ni (wt %) | 11.0–15.0 | 11.0–15.0 |
| Mo (wt %) | 3.0–4.0 | 3.0–4.0 |
| C (wt %) | ≤ 0.08 | ≤ 0.030 |
| Tensile / yield (min, MPa) | 515 / 205 | 515 / 205 |
Frequently asked questions
What is the UNS number of SS 317?
SS 317 is designated UNS S31700.
What is SS 317 used for?
Higher Mo than 316. Typical uses: pulp and paper, fgd, chemical processing.
Is SS 317 magnetic?
Non-magnetic when annealed; may become slightly magnetic after cold work.
In which forms can I buy SS 317 from Rajkamal Metals?
Coils & Strips, Sheets & Plates, Pipes & Tubes, Round Bars & Rods, Structural Sections, Flanges, Buttweld Fittings, Socket Weld & Threaded Fittings, Fasteners, Ferrule / Instrumentation Fittings, Dairy Fittings, Dish Ends, SS Tanks, Custom Orders. Sizes as per standard; other sizes on request.
Do you supply a Mill Test Certificate with SS 317?
Yes. Actual values are given in the Mill Test Certificate (EN 10204 3.1) supplied with each order.
What is the difference between SS 317 and SS 317L?
SS 317: higher mo than 316. SS 317L: low-carbon 317 for welding. See the comparison table on this page.
Last updated: 30 October 2026. Grade names identify the supply range; designations are not engineering equivalents. Availability, make, origin and documentation are confirmed at quotation.
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