ASTM A194
Grade 8MA
Strain-Hardened Nuts
Why 8MA Combines Both Benefits at Once
Molybdenum and cold working solve two entirely different problems, and they don’t interfere with each other — molybdenum is a composition-level addition that improves resistance to chloride-driven pitting and crevice corrosion, while cold working is a mechanical process applied after annealing that raises strength through work hardening. One is chemistry, the other is process, and there’s no reason a nut can’t have both.
Grade 8MA is exactly that combination — the same 316 base material used in Grade 8M, carrying the same genuine molybdenum-driven chloride resistance, then cold worked afterward the same way Grade 8A is derived from Grade 8. Nothing about adding molybdenum prevents strain hardening from working normally, so the strength gain observed going from Grade 8 to 8A carries over essentially the same way going from Grade 8M to 8MA.
That makes 8MA the correct choice specifically when both conditions are genuinely present together — real chloride exposure in the service environment, and a higher-load joint than plain annealed 316 comfortably supports. Specifying it when only one condition applies means paying for a capability the application doesn’t actually use.
Akbar Fasteners Pvt. Ltd. exports to over 50 countries, and our Grade 8MA nut range is verified by chemical composition and mechanical testing under our ISO 9001:2015 quality system.
Where This Grade Genuinely Applies
Genuine Chloride Resistance, Retained
Molybdenum content unaffected by cold working, delivering the same pitting resistance as Grade 8M.
Genuine Strength Gain Added
Cold working delivers the same real work-hardening effect seen going from Grade 8 to 8A.
Correct Choice for Higher-Load Marine Bolting
Reliable where both chloride exposure and elevated mechanical load are genuinely present together.
Verified Mechanical Properties
Batch testing confirms genuine cold-worked strength and molybdenum content for every lot.
Choosing Between Related Stainless Nut Grades
Grade 8M
Same 316 chloride resistance as this page, without the added strength from cold working.
View Grade 8M →Grade 8MA (This Page)
Same 316 chloride resistance as Grade 8M, plus cold-worked strength — both benefits genuinely combined.
You Are HereGrade 8A
Same cold-working strategy as this page, applied to plain 304 rather than chloride-resistant 316.
View Grade 8A →Grade 8M vs Grade 8MA — Quick Reference
Confirming whether the joint genuinely needs the higher strength before paying for the cold-worked variant. This table is the quick reference we use with buyers before quoting.
| Aspect | Grade 8M (Annealed) | Grade 8MA (Strain-Hardened) |
|---|---|---|
| Base Material | AISI 316 | AISI 316, identical composition |
| Process | Solution annealed only | Solution annealed, then cold worked |
| Relative Strength | Moderate | Higher, via work hardening |
| Chloride Resistance | Standard 316 | Identical to Grade 8M |
Grade 8MA 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 Higher Than Grade 8M
- Condition Strain Hardened
- Hardness Elevated Cold-Worked Range
- Chloride Resistance Same as Grade 8M
Fastener Types We Manufacture
- Hex Nuts Standard & Heavy Hex
- Jam Nuts Thin Profile
- Matching Studs ASTM A193 Grade B8MA
- Custom Sizes On Request
Application Areas
Wherever genuine chloride exposure and elevated mechanical load are both present together.
Higher-Load Marine Structural Bolting
elevated mechanical strength
Offshore Pressure Vessel Flanges
resistant flange connections
Desalination High-Load Equipment
equipment with load demands
Coastal Structural Fastening
needing genuine load capacity
Chemical Process High-Load Bolting
chemistry with strength demands
LNG Marine Equipment
cryogenic marine assembly
Coastal Refinery High-Load Piping
higher-torque bolting needs
General Higher-Strength Marine Bolting
needing both benefits together
Standard Export Documentation
Prepared as standard practice for every Grade 8MA nut shipment.
Mill Test Certificate (MTC)
Heat number, chemical composition, and mechanical property verification for every lot.
Mechanical Property Report
Confirms actual cold-worked strength meets the specified Grade 8MA proof load requirement.
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 8M
Our annealed baseline variant of the same 316 base material, without cold working.
View Grade 8M →ASTM A194 Grade 8A
Our strain-hardened 304-based grade, without molybdenum’s chloride resistance.
View Grade 8A →B8M Stud + Gr. 8M Nut Set
Our factory-matched annealed SS316 stud and nut set, for guaranteed thread fit.
View Matched Set →Stainless Steel Fasteners Manufacturer India
Our broader stainless steel fastener manufacturing capability across all major grades.
View SS Manufacturer Guide →Chloride Exposure
Plus Higher Load?
Tell us your service environment and load requirements — we’ll confirm whether Grade 8MA genuinely needs both benefits or whether a simpler grade 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