Stainless Steel 304
304L · 304H
Fasteners Manufacturer
Why Carbon Content Decides Which Stainless Steel 304 304L · 304H Grade Actually Fits
Standard 304 carries up to 0.08% carbon — perfectly fine for the vast majority of general corrosion-resistant fastening, but that carbon can react with chromium during welding heat, forming chromium carbides at grain boundaries that leave the material more vulnerable to intergranular corrosion right where a weld happened. For non-welded fastener applications, this rarely matters in practice.
304L strips carbon down to a maximum of 0.03% specifically to remove that welding vulnerability — the “L” stands for low carbon, and it’s the grade to specify wherever the fastener assembly involves welding or where the tightest corrosion resistance genuinely matters, at a small trade-off in room-temperature strength.
304H does the opposite on purpose — it holds carbon between 0.04% and 0.10%, deliberately higher than standard 304’s typical range, because that carbon actually improves creep resistance and strength retention at sustained elevated temperatures above roughly 500°C, exactly where 304L would be the wrong choice entirely.
Akbar Fasteners Pvt. Ltd. exports to over 50 countries, and our fastener range spans all three carbon variants, verified by chemical composition and mechanical testing under our ISO 9001:2015 quality system.
Where This Material Genuinely Applies
Correct Grade for the Actual Service
Choosing 304, 304L, or 304H by real welding and temperature exposure avoids premature corrosion or failure.
Genuine General Corrosion Resistance
18/8 austenitic composition resists most atmospheric, food-grade, and mild chemical exposure reliably.
Full Weldability Options Available
304L’s low-carbon composition genuinely resolves weld-decay concerns for fabricated assemblies.
Verified Chemical & Mechanical Properties
Batch testing confirms genuine carbon content and mechanical properties for the ordered grade.
304, 304L, and 304H Side by Side
SS 304 — UNS S30400
Standard 18/8 austenitic stainless with up to 0.08% carbon, suited to general non-welded corrosion-resistant fastening across most environments.
Carbon ≤0.08% →SS 304L — UNS S30403
Low-carbon variant with a 0.03% maximum, removing weld-decay risk and maximizing corrosion resistance for welded or critical-service assemblies.
Carbon ≤0.03% →SS 304H — UNS S30409
Controlled higher-carbon variant at 0.04–0.10%, deliberately improving creep strength and stability for sustained elevated-temperature service.
Carbon 0.04–0.10% →304 vs 304L vs 304H — Quick Reference
Confirming welding needs and service temperature before ordering avoids specifying the wrong carbon variant. This table is the quick reference we use with buyers before quoting.
| Aspect | SS 304 | SS 304L | SS 304H |
|---|---|---|---|
| Carbon Content | ≤0.08% | ≤0.03% | 0.04–0.10% |
| Weld Decay Resistance | Standard | Best | Not optimized for this |
| Elevated Temperature Strength | Standard | Lower than 304 | Best (creep resistance) |
| Typical Use | General corrosion resistance | Welded assemblies, critical service | Sustained high-temperature service |
SS 304 / 304L / 304H Specification Details
Nominal Composition
- Chromium 18.0 – 20.0%
- Nickel 8.0 – 10.5%
- Manganese 2.0% Max
- Carbon Grade-Dependent
Typical Mechanical Range
- Tensile Strength 515 MPa Min (Annealed)
- Yield Strength 205 MPa Min (Annealed)
- Hardness ≤201 HB
- Elongation 40% Min
Fastener Types We Manufacture
- Bolts & Studs Hex, Socket, Threaded Rod
- Nuts Hex, Hex Jam, Self-Locking
- Washers Flat, Lock, Spring
- Custom Sizes On Request
Application Areas
Wherever general corrosion resistance, weldability, or elevated-temperature stability genuinely matters.
Food & Beverage Processing
304 fastening
Chemical & Pharmaceutical Plants
corrosion-critical assemblies
Power & Process Piping
elevated-temperature service
Marine & Offshore Structures
structural fastening
Architectural & Facade Hardware
finished-appearance fastening
Water & Wastewater Treatment
for treatment equipment
Fabricated Sheet Metal Assembly
sheet metal structures
General Industrial Assembly
everyday corrosion-resistant needs
Standard Export Documentation
Prepared as standard practice for every SS 304 / 304L / 304H fastener shipment.
Mill Test Certificate (MTC)
Heat number, chemical composition, and mechanical property verification for every lot.
Chemical Composition Report
Confirms actual carbon content falls within the specified grade range — critical for 304L and 304H orders.
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 for critical applications.
Commercial Invoice & Packing List
Itemized value, Incoterm, and detailed carton/weight breakdown for customs clearance.
Internationally Recognised Standards Coverage
Related Fastener Grades & Materials
ASTM A193 B7 / B7M / B6 Stud Bolts
Our alloy steel stud bolt grade guide, a common companion material to stainless fasteners in mixed-material assemblies.
View ASTM A193 Guide →ASTM A193 Grade B8LN
Our low-carbon, nitrogen-enhanced stainless bolting grade, closely related to the 304L family.
View Grade B8LN →Stainless Steel Fasteners Manufacturer India
Our broader stainless steel fastener manufacturing capability across all major grades.
View SS Manufacturer Guide →Stainless Steel Washers
Our dedicated stainless steel washer range, available across the 304/304L/304H family.
View SS Washers →General, Welded, or
High-Temperature — We’ll Confirm the Grade
Tell us whether the assembly involves welding or sustained elevated temperature — we’ll confirm the right carbon variant 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