ASTM F594
Group 1
AISI 304 / 304L Nuts
Why F594 Pairs With F593
ASTM F593 and ASTM F594 are companion specifications — F593 governs externally threaded stainless fasteners (bolts, hex cap screws, and studs), while F594 governs the matching internally threaded nuts, both organized into the same alloy group system so that a Group 1 bolt and a Group 1 nut are guaranteed to be metallurgically matched and dimensionally compatible.
Group 1 under F594 is manufactured from the same 18% chromium, 8% nickel austenitic composition as its F593 bolt counterpart — the same well-balanced, broadly corrosion-resistant chemistry suited to general atmospheric, food-contact, mild chemical, and architectural service. The 304L variant carries the same low-carbon distinction as its bolt counterpart, specifically reducing sensitization risk in nuts used near welded assemblies.
Specifying matched F593/F594 Group 1 bolts and nuts together avoids a genuine, practical mismatch risk — pairing a stainless bolt with a nut of unknown or mismatched grade can introduce galvanic or strength incompatibilities at the joint, so buyers assembling a complete fastened connection benefit from confirming both halves come from the same alloy group.
Akbar Fasteners Pvt. Ltd. exports to over 50 countries, and our ASTM F594 Group 1 nut range is manufactured and verified by chemical composition and mechanical testing under our ISO 9001:2015 quality system.
A Note on Matched Assemblies
We recommend ordering F593 Group 1 bolts/studs and F594 Group 1 nuts together as a matched set whenever practical, to confirm consistent alloy chemistry and mechanical properties across the full fastened joint. Let us know if you’d like both quoted together.
Where This Material Genuinely Applies
Genuine, Broad Corrosion Resistance
Well-balanced chromium and nickel content for general atmospheric and mild chemical exposure.
Guaranteed Bolt Compatibility
Matched alloy group system ensures dimensional and metallurgical compatibility with F593 bolts.
304L Weld-Decay Protection
Low carbon content genuinely reduces sensitization risk near welded assemblies.
Verified Mechanical Properties
Batch testing confirms genuine alloy content and mechanical properties for every lot.
F594 Group 1 vs Group 2 — Quick Reference
Confirming whether chloride exposure genuinely requires Group 2’s added molybdenum before paying for the higher grade. This table is the quick reference we use with buyers before quoting.
| Aspect | F594 Group 1 (304/304L) | F594 Group 2 (316/316L) |
|---|---|---|
| Base Composition | 18% Cr, 8% Ni | 16-18% Cr, 10-14% Ni, +Mo |
| Chloride/Pitting Resistance | Good, general exposure | Genuinely superior, molybdenum-enhanced |
| Matching Bolt Standard | ASTM F593 Group 1 | ASTM F593 Group 2 |
| Best Suited For | General atmospheric, food, mild chemical | Marine, coastal, or chloride-heavy service |
F594 Group 1 Specification Details
Nominal Composition
- Chromium 18.0 – 20.0%
- Nickel 8.0 – 10.5%
- Carbon (304) ≤0.08%
- Carbon (304L) ≤0.03%
Typical Mechanical Range
- Condition Cold Worked / Annealed
- Corrosion Resistance General Atmospheric & Mild Chemical
- Matching Bolt Standard ASTM F593 Group 1
- Fastener Standard ASTM F594 Group 1
Fastener Types We Manufacture
- Hex Nuts Standard & Heavy Hex
- Jam Nuts Thin Profile
- Matching Bolts & Studs ASTM F593, On Request
- Washers Matching Material
Application Areas
Wherever general corrosion resistance is needed without the specific chloride/marine exposure that would call for Group 2 instead.
Food Processing & Kitchen Equipment
hygienic equipment
Architectural & Structural Fastening
exterior and interior fastening
Chemical & Pharmaceutical Equipment
equipment fastening
General Industrial & Piping Applications
resistant fastening needs
Standard Export Documentation
Prepared as standard practice for every ASTM F594 Group 1 nut shipment.
Mill Test Certificate (MTC)
Heat number, chemical composition, and mechanical property verification for every lot.
Chemical Composition Report
Confirms actual chromium, nickel, and carbon content fall within the specified 304/304L 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 and dimensional 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 F593 Group 1 (304/304L)
Our companion bolt, hex cap screw, and stud specification, for a complete matched Group 1 assembly.
View F593 Group 1 →ASTM F594 Group 2 (316/316L)
Our higher chloride-resistance nut grade, for marine or coastal service beyond Group 1’s range.
View F594 Group 2 →ASTM A194 Grade 8 Nuts
Our standard 304-equivalent A194 stainless nut grade, an alternative dimensional standard family.
View Grade 8 Nuts →Stainless Steel Fasteners Manufacturer India
Our broader fastener manufacturing capability across all major carbon, alloy, stainless, and non-ferrous grades.
View SS Manufacturer Guide →Need Matching Nuts
for Your F593 Bolts?
Tell us your application and whether welding is involved nearby — we’ll confirm whether 304 or 304L fits, and quote your complete matched bolt-and-nut assembly with full documentation. Akbar Fasteners Pvt. Ltd. responds within 24 hours.
Sales: +91 724 0000 733 · Support: +91 800 9315 333 · sales@akbarfasteners.in