Stainless Steel 317
Fasteners
Manufacturer · Mumbai
Why Stainless Steel 317 Fasteners Genuinely Exists as Its Own Grade
316’s roughly 2–3% molybdenum content is genuinely enough for most marine and general chemical exposure — but pulp and paper bleaching liquors, sulfuric and phosphoric acid environments, and certain flue gas desulfurization conditions push chloride and acid attack past what 316’s passive film can reliably hold up against over the long term.
317 answers that specific gap by raising molybdenum to roughly 3–4% — a meaningful jump that measurably improves resistance to both pitting corrosion and general acid attack compared to 316, without requiring a jump to a fully specialty nickel alloy like Hastelloy or Inconel, which carries a substantially higher cost and different fabrication considerations entirely.
That positioning is exactly what makes 317 useful — it’s the sensible next step when 316 genuinely isn’t holding up, before reaching for something far more expensive that the application may not actually require.
Akbar Fasteners Pvt. Ltd. exports to over 50 countries, and our SS 317 fastener range is verified by chemical composition and mechanical testing under our ISO 9001:2015 quality system.
Where This Material Genuinely Applies
Genuine Step-Up From 316
Higher molybdenum measurably improves pitting and acid resistance where 316 falls short.
Cost-Sensible Positioning
Solves aggressive corrosion needs without the cost premium of specialty nickel alloys.
Genuine Acid Resistance
Improved resistance to sulfuric and phosphoric acid environments beyond standard 316.
Verified Chemical & Mechanical Properties
Batch testing confirms genuine molybdenum content and mechanical properties for every lot.
304 → 316 → 317 — a Clear Progression
SS 304
No molybdenum. Genuinely sufficient for general atmospheric and mild corrosion resistance, non-chloride environments.
View SS 304 → Step 2 — Marine GradeSS 316
2–3% molybdenum. The standard choice for chloride exposure, marine hardware, and general chemical processing.
View SS 316 →SS 317 (This Page)
3–4% molybdenum. The next step up when 316 genuinely isn’t sufficient, before specialty nickel alloys.
You Are Here316 vs 317 — Quick Reference
Confirming genuine 316 failure history or documented environment severity avoids overpaying for capability the application may not need. This table is the quick reference we use with buyers before quoting.
| Aspect | SS 316 | SS 317 |
|---|---|---|
| Molybdenum Content | 2.0–3.0% | 3.0–4.0% |
| Chloride Pitting Resistance | Good | Better |
| Acid Environment Resistance | Moderate | Improved |
| Typical Use | General marine/chemical | Pulp/paper, acid process, severe chloride |
| Cost Tier | Standard | Higher than 316, well below specialty alloys |
SS 317 Specification Details
Nominal Composition
- Chromium 18.0 – 20.0%
- Nickel 11.0 – 15.0%
- Molybdenum 3.0 – 4.0%
- Carbon ≤0.08%
Typical Mechanical Range
- Tensile Strength 515 MPa Min (Annealed)
- Yield Strength 205 MPa Min (Annealed)
- Hardness ≤217 HB
- Elongation 35% Min
Fastener Types We Manufacture
- Bolts & Studs Hex, Socket, Threaded Rod
- Nuts Hex, Hex Jam
- Washers Flat, Lock, Spring
- Custom Sizes On Request
Application Areas
Wherever 316 genuinely isn’t sufficient, but a specialty nickel alloy isn’t yet necessary.
Pulp & Paper Bleaching Equipment
liquor chemical attack
Sulfuric Acid Process Equipment
corrosion resistance
Flue Gas Desulfurization Systems
acidic flue gas exposure
Severe Chloride Marine Environments
documented pitting history
Chemical Processing Plants
chemical exposure
Flue & Stack Gas Handling
chloride gas exposure
Textile & Dye Processing
chemical dye processes
General High-Severity Chemical Assembly
documented insufficient resistance
Standard Export Documentation
Prepared as standard practice for every SS 317 fastener shipment.
Mill Test Certificate (MTC)
Heat number, chemical composition, and mechanical property verification for every lot.
Chemical Composition Report
Confirms actual molybdenum content falls within the specified 317 grade range.
Certificate of Conformance
Confirms the shipment matches the purchase order grade/size specification in full.
Certificate of Origin (COO)
Confirms India as country of manufacture for destination customs purposes.
NABL Accredited Test Reports
Independent mechanical, dimensional, and pitting resistance testing available on request.
Commercial Invoice & Packing List
Itemized value, Incoterm, and detailed carton/weight breakdown for customs clearance.
Internationally Recognised Standards Coverage
Related Fastener Grades & Materials
SS 316 / 316L / 316H Fasteners
Our marine-grade stainless family, and where 316 remains genuinely sufficient instead of 317.
View SS 316 Guide →SS 304 / 304L / 304H Fasteners
Our general-purpose stainless family for non-chloride, non-acid environments.
View SS 304 Guide →High-Nickel Alloy Fasteners
Our specialty nickel alloy range for environments beyond what 317 can reliably handle.
View High-Nickel Guide →Stainless Steel Fasteners Manufacturer India
Our broader stainless steel fastener manufacturing capability across all major grades.
View SS Manufacturer Guide →When 316 Isn’t Enough,
Before You Reach for Specialty Alloys
Tell us the environment and any 316 failure history — we’ll confirm whether 317 genuinely fits and quote with full documentation. Akbar Fasteners Pvt. Ltd. responds within 24 hours.
Sales: +91 724 0000 733 · Support: +91 800 9315 333 · sales@akbarfasteners.in