ASTM A193
Grade B8LN
AISI 304LN Bolts
Why Nitrogen Genuinely Buys Back Strength
Standard 304L already answers the weld-decay problem — dropping carbon to a 0.03% maximum removes most of the chromium carbide precipitation risk that plain 304 carries during and after welding. That’s a genuinely effective fix, but carbon itself contributes to strength in austenitic stainless, so stripping it out has a real, measurable cost in yield and tensile strength.
304LN answers that cost directly — nitrogen is added in a controlled amount specifically because it increases strength in austenitic stainless through a mechanism separate from carbon entirely, letting the alloy recover much of the strength that low-carbon composition alone gave up, all while keeping the exact same weld-decay resistance that made the low-carbon choice necessary in the first place.
That combination is exactly why B8LN exists as its own ASTM A193 grade — buyers who need genuine weld-decay resistance for fabricated, high-temperature, or corrosion-critical assemblies, but also can’t accept the strength penalty of plain 304L alone, have a real reason to specify B8LN by name rather than defaulting to a standard low-carbon grade.
Akbar Fasteners Pvt. Ltd. exports to over 50 countries, and our B8LN stud bolt range is verified by chemical composition and mechanical testing under our ISO 9001:2015 quality system.
Where This Grade Genuinely Applies
Genuine Weld-Decay Resistance
Low-carbon composition removes chromium carbide precipitation risk during welding.
Strength Advantage Over Plain 304L
Nitrogen addition recovers strength that low carbon alone would otherwise sacrifice.
Correct Choice for Welded, Corrosion-Critical Bolting
Reliable where both weld integrity and mechanical strength genuinely matter together.
Verified Chemical & Mechanical Properties
Batch testing confirms genuine carbon and nitrogen content for the ordered grade.
B8 → B8L → B8LN — a Clear Progression
Grade B8 (AISI 304)
Standard carbon content, up to 0.08%. Genuinely sufficient for general, non-welded corrosion-resistant bolting.
General PurposeGrade B8L (AISI 304L)
Carbon dropped to 0.03% maximum specifically to resolve weld-decay risk, at a real cost in room-temperature strength.
Weld-Decay Fix, Strength Trade-OffGrade B8LN (This Page)
Same weld-decay resistance as B8L, with nitrogen added specifically to recover the strength the low-carbon composition otherwise gives up.
You Are HereB8L vs B8LN — Quick Reference
Confirming whether the application genuinely needs the strength recovery, or whether plain B8L is sufficient, avoids overspecifying. This table is the quick reference we use with buyers before quoting.
| Aspect | Grade B8L (304L) | Grade B8LN (304LN) |
|---|---|---|
| Carbon Content | ≤0.03% | ≤0.03% |
| Nitrogen Addition | None | Controlled addition |
| Weld-Decay Resistance | Excellent | Excellent, same mechanism |
| Relative Strength | Lower than standard 304 | Recovered, closer to standard 304 |
B8LN Specification Details
Nominal Composition
- Chromium 18.0 – 20.0%
- Nickel 8.0 – 10.5%
- Carbon ≤0.03%
- Nitrogen 0.10 – 0.16%
Typical Mechanical Range
- Tensile Strength ~550 MPa Min
- Yield Strength ~240 MPa Min
- Hardness ≤217 HB
- Elongation 35% Min
Fastener Types We Manufacture
- Stud Bolts Continuous & Double-End
- Hex Bolts Standard & Heavy Hex
- Matching Nuts ASTM A194 Grade 8LN
- Custom Sizes On Request
Application Areas
Wherever weld-decay resistance and recovered mechanical strength are both genuinely needed.
Welded Chemical Process Equipment
recovered mechanical strength
Cryogenic & LNG Equipment
for low-temperature service
Pharmaceutical Fabricated Assemblies
equipment fastening
Food & Beverage Processing
fastening applications
Fabricated Sheet Metal Structures
both decay resistance and strength
Water & Wastewater Treatment
with strength requirements
Power Plant Piping & Vessels
needing recovered strength
General Welded Corrosion-Resistant Bolting
needing both properties together
Standard Export Documentation
Prepared as standard practice for every B8LN bolt shipment.
Mill Test Certificate (MTC)
Heat number, chemical composition, and mechanical property verification for every lot.
Chemical Composition Report
Confirms actual carbon and nitrogen content fall within the specified B8LN 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 A193 Grade B8CLN / B8CLNA
Our niobium-stabilized, nitrogen-enhanced grade family based on 347LN.
View B8CLN / B8CLNA →SS 304 / 304L / 304H Fasteners
Our broader 304 family guide, covering the base carbon-variant logic B8LN builds on.
View SS 304 Guide →ASTM A193 B7 / B7M / B6
Our alloy steel stud bolt grade guide, for non-stainless bolting applications.
View ASTM A193 Guide →Stainless Steel Fasteners Manufacturer India
Our broader stainless steel fastener manufacturing capability across all major grades.
View SS Manufacturer Guide →Weld-Decay Resistance,
Without the Strength Penalty
Tell us your welding and strength requirements — we’ll confirm whether B8LN genuinely fits or whether plain B8L 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