ASTM A194
Grade 8M
Stainless Steel Nuts
Why 8M Genuinely Differs From Grade 8
Grade 8, plain 304 stainless, handles a wide range of general corrosion exposure well — but 304-series stainless was never specifically built to resist chloride-driven pitting and crevice corrosion, the particular failure mode that shows up in seawater, de-icing salts, and many chemical process streams.
Grade 8M answers that specific gap — the base material shifts entirely from 304 to 316, and that shift is defined by one deliberate addition: roughly 2–3% molybdenum. That’s the entire distinction between these two grades. Everything else — general strength range, weld characteristics, dimensional standards — carries over unchanged.
That makes the choice between Grade 8 and Grade 8M a genuinely simple question — is chloride exposure actually present in the service environment? If yes, molybdenum’s pitting resistance earns its modest cost premium. If the environment is a general, non-chloride corrosive exposure, plain Grade 8 performs equally well at lower cost.
Akbar Fasteners Pvt. Ltd. exports to over 50 countries, and our Grade 8M nut range is verified by chemical composition and mechanical testing under our ISO 9001:2015 quality system.
Where This Grade Genuinely Applies
Genuine Chloride & Pitting Resistance
Molybdenum content delivers real resistance to chloride-driven pitting and crevice corrosion.
Correct Default Pairing With B8M Studs
Matched material and mechanical properties for straightforward assembly compatibility.
Correct Choice for Marine & Chemical Service
Reliable where seawater, de-icing salts, or chloride-bearing process chemistry are present.
Verified Chemical & Mechanical Properties
Batch testing confirms genuine molybdenum content and mechanical properties for every lot.
Choosing Between Related Stainless Nut Grades
Grade 8
Plain 304, annealed. Genuinely sufficient general corrosion resistance without chloride-critical exposure.
View Grade 8 →Grade 8M (This Page)
Same annealed condition and general logic as Grade 8, with molybdenum added specifically for chloride resistance.
You Are HereGrade 8MLN / 8MLNA (316LN Base)
Adds low-carbon weld-decay resistance and nitrogen-recovered strength on top of Grade 8M’s molybdenum base — see our B8MLN/B8MLNA grade page.
View B8MLN / B8MLNA →Grade 8 vs Grade 8M — Quick Reference
Confirming whether chloride exposure is genuinely present decides between these two closely related grades. This table is the quick reference we use with buyers before quoting.
| Aspect | Grade 8 (304) | Grade 8M (316) |
|---|---|---|
| Molybdenum Content | None | ~2–3% |
| Chloride / Pitting Resistance | Standard | Genuinely improved |
| General Corrosion Resistance | Excellent | Excellent, same base logic |
| Best Suited For | General, non-chloride exposure | Marine, chloride-bearing exposure |
Grade 8M Specification Details
Nominal Composition
- Chromium 16.0 – 18.0%
- Nickel 10.0 – 14.0%
- Molybdenum 2.0 – 3.0%
- Carbon ≤0.08%
Typical Mechanical Range
- Proof Load Per ASTM A194 Grade 8M
- Condition Solution Annealed
- Hardness Standard Annealed Range
- Corrosion Resistance Chloride-Resistant
Fastener Types We Manufacture
- Hex Nuts Standard & Heavy Hex
- Jam Nuts Thin Profile
- Matching Studs ASTM A193 Grade B8M
- Custom Sizes On Request
Application Areas
Wherever genuine chloride or marine exposure is present alongside a need for corrosion-resistant bolting.
Marine & Offshore Structures
and fastening applications
Coastal & De-Icing Salt Exposure
and roadway environments
Chemical Process Equipment
chemistry equipment
Desalination Plant Equipment
equipment fastening
Pulp & Paper Chloride-Bearing Process
chloride exposure
Pharmaceutical & Food Processing
equipment fastening
Coastal Refinery Piping
in piping and flange bolting
General Marine-Grade Bolting
needing chloride resistance
Standard Export Documentation
Prepared as standard practice for every Grade 8M nut 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 316 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 corrosion 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
ASTM A194 Grade 8
Our 304-based baseline stainless nut grade, without molybdenum’s chloride resistance.
View Grade 8 →ASTM A194 Grade 8A
Our strain-hardened 304-based grade, for higher-strength applications without chloride exposure.
View Grade 8A →ASTM A193 Grade B8MLN / B8MLNA
Our low-carbon, nitrogen-enhanced 316LN-based variant, for weld-critical marine service.
View B8MLN / B8MLNA →Stainless Steel Fasteners Manufacturer India
Our broader stainless steel fastener manufacturing capability across all major grades.
View SS Manufacturer Guide →Chloride Exposure?
We’ll Confirm the Right Grade
Tell us your service environment — we’ll confirm whether Grade 8M genuinely fits or whether plain Grade 8 is sufficient, 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