Hastelloy B3
Washers
What Makes Hastelloy B3 Different
Hastelloy B3 (UNS N10675 / DIN 2.4600) is a third-generation Ni-Mo superalloy developed to address the thermal instability of its predecessors, B and B2. The addition of chromium, iron, and tungsten in precise proportions eliminates ordered intermetallic phase formation during slow cooling — a critical advantage for thick-section fasteners and washers that spend time in the 700–1200°C temperature range during manufacture.
With 28–33% molybdenum content, B3 delivers the highest resistance to reducing acid environments available in a commercially produced alloy. It outperforms SS 316L, Duplex 2205, and even Hastelloy C276 in pure HCl service — making it the specification-of-choice for chemical reactor lining fasteners, HCl synthesis plant assemblies, and pharmaceutical hydrogenation equipment.
B3 washers from Akbar Fasteners Pvt. Ltd. are manufactured from certified mill bar stock, PMI-verified on receipt, and supplied with full MTC, Certificate of Conformance, and NABL-accredited mechanical test reports.
| Element | % Min | % Max | Typical |
|---|---|---|---|
| Nickel (Ni) | Balance | Balance | ~65% |
| Molybdenum (Mo) | 27.0 | 32.0 | ~30% |
| Chromium (Cr) | 1.0 | 3.0 | ~1.5% |
| Iron (Fe) | 1.0 | 3.0 | ~2.0% |
| Cobalt (Co) | — | 3.0 | — |
| Tungsten (W) | 2.5 | 4.0 | ~3.0% |
| Manganese (Mn) | — | 3.0 | — |
| Silicon (Si) | — | 0.10 | <0.1% |
| Carbon (C) | — | 0.01 | <0.01% |
| Phosphorus (P) | — | 0.03 | — |
| Sulfur (S) | — | 0.03 | — |
Hastelloy B3 Washer Types
All types available in Hastelloy B3 with full dimensional documentation and material certification.
Plain Flat Washers
Standard flat face washers for load distribution under bolt heads and nuts. DIN 125 / ISO 7089. M5 to M100. Flat bearing face, chamfered or plain edge.
Spring / Lock Washers
Split ring and Belleville spring washers for vibration-resistant assemblies. DIN 127. Provides ongoing clamp load in thermal cycling environments.
Toothed Lock Washers
Internal, external and tooth-lock washers for positive locking action. DIN 6798. Prevents loosening under vibration without additional fasteners.
Large OD / Fender Washers
Oversized OD washers for applications requiring greater load distribution area. Custom OD available. Flanged piping, pressure vessel assemblies.
Standard Sizes — Plain Flat Washers
Dimensions per DIN 125-A / ISO 7089. Custom OD, ID, and thickness available on request. All dimensions in mm.
| Bolt Size | ID (d₁) mm | OD (d₂) mm | Thickness mm | Weight kg/pc | Standard |
|---|---|---|---|---|---|
| M5 | 5.3 | 10 | 1.0 | 0.00052 | DIN 125-A |
| M6 | 6.4 | 12 | 1.6 | 0.00125 | DIN 125-A |
| M8 | 8.4 | 16 | 1.6 | 0.00228 | DIN 125-A |
| M10 | 10.5 | 20 | 2.0 | 0.00503 | DIN 125-A |
| M12 | 13.0 | 24 | 2.5 | 0.00868 | DIN 125-A |
| M16 | 17.0 | 30 | 3.0 | 0.01583 | DIN 125-A |
| M20 | 21.0 | 37 | 3.0 | 0.02347 | DIN 125-A |
| M24 | 25.0 | 44 | 4.0 | 0.04389 | DIN 125-A |
| M30 | 31.0 | 56 | 4.0 | 0.07234 | DIN 125-A |
| M36 | 37.0 | 66 | 5.0 | 0.12390 | DIN 125-A |
| M42 | 43.0 | 78 | 7.0 | 0.22770 | DIN 125-A |
| M48 | 50.0 | 92 | 8.0 | 0.36460 | ISO 7089 |
| M56 | 58.0 | 105 | 9.0 | 0.54130 | ISO 7089 |
| M64 | 66.0 | 115 | 9.0 | 0.61870 | ISO 7089 |
| M72 | 74.0 | 125 | 10.0 | 0.76540 | ISO 7089 |
| M80 | 82.0 | 140 | 12.0 | 1.24650 | ISO 7089 |
| M90 | 93.0 | 155 | 14.0 | 1.72340 | Custom |
| M100 | 104.0 | 175 | 16.0 | 2.54110 | Custom |
* Custom OD, ID, thickness and non-standard sizes manufactured on request — sales@akbarfasteners.in
Standards We Manufacture To
Every Hastelloy B3 washer is manufactured, tested, and certified to the applicable international standard.
Where Hastelloy B3 Washers Are Used
B3’s superior HCl resistance makes it irreplaceable in specific high-corrosion industrial environments where SS and other alloys fail.
HCl Synthesis Plants
fastener assemblies
Chemical Processing
reducing acid environments
Pharmaceutical
reactor vessels
Pulp & Paper
digesters
Oil & Gas
subsea equipment
Petrochemical
acid catalyst systems
Semiconductor
HCl gas handling
Fertiliser Plants
and fluoride service
Full Documentation Package
Heat & Lot Traceable
Conformance
XRF Verified
Tensile · Hardness
TÜV · BV · Lloyds
Need Hastelloy B3
Washers Fast?
Send us your size, quantity, standard, and documentation requirements. We respond within 24 hours with pricing, lead time, and documentation list.