ASTM A194
Grade 8A
Strain-Hardened Nuts
Why Strain Hardening Genuinely Raises Strength
304 austenitic stainless doesn’t harden through heat treatment the way alloy steel does — quenching and tempering, the mechanism that gives grades like ASTM A194 Grade 2H their strength, simply doesn’t apply to this material family. If a genuinely higher-strength stainless nut is needed without changing the base chemistry, the strength has to come from somewhere else.
Cold working supplies that “somewhere else” — deforming the annealed 304 material below its recrystallization temperature through controlled mechanical working genuinely increases yield and tensile strength, a real metallurgical effect called work hardening or strain hardening, where dislocations introduced during deformation make further deformation progressively harder.
That’s the entire distinction behind Grade 8A — identical 304 composition, identical general corrosion resistance to Grade 8, but processed through controlled cold working afterward specifically to raise mechanical strength for higher-load bolted joints where plain annealed 304 doesn’t provide quite enough margin.
Akbar Fasteners Pvt. Ltd. exports to over 50 countries, and our Grade 8A nut range is verified by chemical composition and mechanical testing under our ISO 9001:2015 quality system.
Where This Grade Genuinely Applies
Genuine Strength Gain Without Alloy Change
Cold-working delivers real mechanical strength increase while keeping identical 304 corrosion resistance.
Correct Choice for Higher-Load Stainless Joints
Reliable where plain annealed Grade 8 leaves insufficient strength margin.
Correct Default Pairing With B8A Studs
Matched material and mechanical properties for straightforward assembly compatibility.
Verified Mechanical Properties
Batch testing confirms genuine cold-worked strength meets the specified grade requirement.
Choosing Between Related Stainless Nut Grades
Grade 8
Plain 304, solution annealed. The starting point Grade 8A is deliberately strengthened from through cold working.
View Grade 8 →Grade 8A (This Page)
Same 304 composition as Grade 8, cold worked afterward specifically for higher mechanical strength.
You Are HereGrade 8MLNA (316LN Base)
Same strain-hardening logic applied to a molybdenum-bearing 316LN base — see our B8MLN/B8MLNA grade page.
View B8MLNA Reference →Grade 8 vs Grade 8A — 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 8 (Annealed) | Grade 8A (Strain-Hardened) |
|---|---|---|
| Base Material | AISI 304 | AISI 304, identical composition |
| Process | Solution annealed only | Solution annealed, then cold worked |
| Relative Strength | Moderate | Higher, via work hardening |
| Corrosion Resistance | Standard 304 | Identical to Grade 8 |
Grade 8A Specification Details
Nominal Composition
- Chromium 18.0 – 20.0%
- Nickel 8.0 – 10.5%
- Carbon ≤0.08%
- Iron Balance
Typical Mechanical Range
- Proof Load Higher Than Grade 8
- Condition Strain Hardened
- Hardness Elevated Cold-Worked Range
- Corrosion Resistance Same as Grade 8
Fastener Types We Manufacture
- Hex Nuts Standard & Heavy Hex
- Jam Nuts Thin Profile
- Matching Studs ASTM A193 Grade B8A
- Custom Sizes On Request
Application Areas
Wherever plain 304 corrosion resistance is right but Grade 8’s annealed strength margin isn’t quite enough.
Higher-Load Chemical Process Bolting
elevated mechanical strength
Structural Stainless Assembly
resistant structural bolting
Food & Beverage High-Load Equipment
higher clamping requirements
Marine & Coastal Structural Bolting
needing elevated strength
Pressure Vessel Flange Bolting
flange connections
Architectural Load-Bearing Fastening
with genuine load requirements
General Equipment Requiring Higher Torque
corrosion-resistant assembly
General Higher-Strength Stainless Bolting
needing 304 strength beyond Grade 8
Standard Export Documentation
Prepared as standard practice for every Grade 8A 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 8A 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 8
Our annealed baseline variant of the same 304 base material, without cold working.
View Grade 8 →ASTM A193 Grade B8MLN / B8MLNA
Our molybdenum-bearing 316LN-based variant, for chloride and marine service.
View B8MLN / B8MLNA →ASTM A194 Grade 6 / 6F
Our heat-treated carbon steel nut grade, for non-stainless general bolting needs.
View Grade 6 / 6F →Stainless Steel Fasteners Manufacturer India
Our broader stainless steel fastener manufacturing capability across all major grades.
View SS Manufacturer Guide →Need Extra Strength
Without Changing the Alloy?
Tell us your load requirements — we’ll confirm whether Grade 8A’s cold-worked strength 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