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Hastelloy B3 Bolts Manufacturer & Exporter in India

Explore Hastelloy B3 Bolts Manufacturer & Exporter in India manufactured for demanding industrial applications with reliable strength, corrosion resistance and compliance with international standards.
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-200

Min Temp

1100

Max Temp

🌡

1100

Suitable for continuous service up to approximately 1100°C under typical operating conditions.

⚡

800

Typical tensile strength around 800 MPa depending on product form and heat treatment.

🛡

Excellent

Excellent corrosion resistance in a wide range of industrial environments.

⚖

8.9

Typical density is approximately 8.9 g/cm³.

Product Overview

What are Hastelloy B3 Bolts?

Hastelloy B3 bolts are nickel-molybdenum alloy fasteners machined from UNS N10675 bar stock conforming to ASTM B335. The alloy’s exceptionally high molybdenum content (28.5-31.5%) delivers outstanding resistance to hydrochloric acid at all concentrations and temperatures, including boiling HCl – a performance level unmatched by any stainless steel or standard nickel alloy.

The addition of chromium (1.0-3.0%) and iron (3.0% max) in B3 over its predecessor B2 significantly reduces the risk of thermally induced precipitation, improving fabrication reliability and long-term stability in process environments. Hastelloy B3 bolts are specified for chemical reactor closures, acid distillation column flanges, and hydrochloric acid handling systems where fastener corrosion failure is not an option.

Quick Specifications

MaterialHastelloy B3
UNS NumberN10675
DIN Number2.4600
Material StandardASTM B335
Bolt Standard (Metric)DIN 931 / DIN 933 / ISO 4014
Bolt Standard (Inch)ASME B18.2.1
Thread FormISO Metric / UNC / UNF
Diameter RangeM6-M100 / ¼"-4"
Tensile Strength760 MPa (110 ksi) min
Yield Strength350 MPa (51 ksi) min
HardnessMax 35 HRC / 241 HB
? All material certified by NABL-accredited laboratory. PMI available on request.

Complete the Fastener Set

Other Hastelloy B3 Fastener Products Available from RealBolt

RealBolt also manufactures the complete Hastelloy B3 fastener range from certified nickel-molybdenum-chromium superalloy bar stock, including Hastelloy B3 Nuts, Hastelloy B3 Screws, Hastelloy B3 Washers, Hastelloy B3 Studs, and Hastelloy B3 Threaded Rods. All Hastelloy B3 fastener types are produced to ASTM with full EN 10204 MTC 3.1/3.2 documentation.
Hastelloy B3 Nuts
Hastelloy B3 Screws
Hastelloy B3 Washers
Hastelloy B3 Studs
Hastelloy B3 Threaded Rods

Technical Data

Hastelloy B3 Bolts Dimensions, Sizes & Thread Standards

Hastelloy B3 Bolts are available in metric M6–M100 and inch ¼″–4″ as standard. Per DIN 931 (partial thread) / DIN 933 (full thread) / ISO 4014. Custom lengths in 5mm increments. Inch dimensions available per ASME B18.2.1. All Hastelloy B3 bolts dimensions are verified against applicable DIN, ISO, and ASME

Hex Bolt Dimensions - Metric (DIN 931 / ISO 4014)

Size (M)Pitch (mm)A/F (mm)Head Ht (mm)Min L (mm)Max L (mm)
M61.0104.010200
M81.25135.312250
M101.5176.416300
M121.75197.520400
M162.02410.025500
M202.53012.530600
M243.03615.040600
M303.54618.750800
M364.05522.5601000
M424.56526.0801000
M485.07530.01001200
M565.58535.01201500
M646.09540.01402000
M726.010545.01602000
M806.011550.01802500
M1006.014563.02003000

Dimensional & Material Standards

StandardCoversThread
DIN 931Hex bolts, partial threadMetric
DIN 933Hex bolts, full threadMetric
ISO 4014Hex head screws, partialMetric
ISO 4017Hex head screws, fullMetric
ASME B18.2.1Hex & heavy hex boltsUNC/UNF
ASME B16.5Stud bolts for flangesUNC
MSS SP-75Stud bolts, high-pressureUNC
Material StandardRequirement
ASTM B335Bar/rod - UNS N10675
ASTM B462Forgings - UNS N10675
ASTM F468Fastener mechanical properties
EN 10204 3.1Mill test certificate
EN 10204 3.2TPI-witnessed MTC

Material Chemistry

Hastelloy B3 Chemical Composition

Hastelloy B3 Bolts derive their exceptional acid corrosion resistance from a precisely controlled nickel-molybdenum-chromium composition per ASTM. High molybdenum and tungsten content suppresses pitting and reducing-acid attack; ultra-low carbon (0.01% max) eliminates sensitization risk in welded assemblies. Full elemental composition is certified in the EN 10204 MTC supplied with every Hastelloy B3 bolts order from RealBolt.

Chemical Composition per ASTM B335

ElementComposition (%)
Nickel (Ni)Balance (approx. 65% min)
Molybdenum (Mo)28.5-31.5%
Chromium (Cr)1.0-3.0%
Iron (Fe)3.0% max
Cobalt (Co)3.0% max
Manganese (Mn)3.0% max
Aluminium (Al)0.5% max
Carbon (C)0.01% max
Silicon (Si)0.10% max
Tungsten (W)3.0% max
? All heats verified by NABL-accredited spectrometry. PMI available on request.

Why Hastelloy B3 Alloy Composition Matters for Bolts

Mo (28.5–31.5%) — Hydrochloric Acid Immunity
The ultra-high molybdenum content is the defining characteristic of Hastelloy B3. It provides complete resistance to hydrochloric acid at all concentrations up to boiling point — including under bolt head bearing surfaces where crevice conditions accelerate corrosion in lesser alloys.
Cr (1.0–3.0%) — Improved Thermal Stability Over B2
The controlled chromium addition in B3 suppresses the formation of Ni4Mo precipitates that plagued Hastelloy B2 in the heat-affected zone during welding and slow cooling. B3 bolts can be used in welded assemblies without the risk of intergranular attack that limited B2 applications.
Ultra-Low Carbon (0.01% max) — Grain Boundary Protection
The extremely low carbon ceiling prevents carbide precipitation at grain boundaries during thermal exposure, maintaining full corrosion resistance across the entire fastener cross-section — critical for large-diameter bolts with slower cooling rates during solution annealing.

Fastener Performance

Hastelloy B3 Bolts Mechanical Properties & Torque Reference

The table below lists mechanical properties and torque reference for Hastelloy B3 Bolts per ASTM. Hastelloy B3 bolts achieve 800 MPa tensile strength, with hardness, yield, and elongation values verified by NABL-accredited testing and reported in the EN 10204 MTC.

Tightening Torque Reference - Hastelloy B3 Hex Bolts

Bolt SizeDry (Nm)Lubricated (Nm)Clamp Load (kN)
M12826630
M1619815872
M20395316115
M24685548167
M3013701096265
M3623801904385
M4238003040530
M4856404512698
?? Anti-galling: Use nickel-based anti-seize (Molykote P-37 or equivalent). Lubricated values assume K=0.15. Never use copper-based anti-seize on nickel-molybdenum alloys - galvanic incompatibility accelerates thread corrosion in acid environments.

Industry Applications

Hastelloy B3 Bolts Applications — Industries & End Uses

Hastelloy B3 Bolts from RealBolt are specified across chemical processing, pharmaceutical, oil and gas, and FGD where excellent corrosion resistance and 800 MPa tensile strength are required for reliable fastener performance. Click each industry below for detailed application examples. Select an industry below to see specific Hastelloy B3 bolts application details and RealBolt stock availability.
Hastelloy B3 stud bolts and hex bolts are the primary specification for flanged connections on HCl synthesis columns, acid storage tank nozzles, and pickling line piping systems. The alloy withstands boiling HCl at all concentrations where no stainless steel or standard nickel alloy can survive. Supplied per ASTM B335 with EN 10204 3.1 MTC.
Reactor closure bolting, agitator flange connections, and pressure vessel nozzle stud bolt sets in pharmaceutical API synthesis where reducing acid environments – including dilute HCl, H2SO4, and acetic acid mixtures – demand fastener materials that will not contaminate the product stream through corrosion byproducts.
Flange bolt sets for chlorine dioxide bleaching tower connections, digester pressure vessel closures, and black liquor evaporator nozzles. Hastelloy B3 bolts resist the combined attack of reducing acids and elevated temperatures encountered in kraft pulping and bleaching circuits where 316L stainless fails within months.
Bolting for pressure oxidation autoclave flanges, acid leach reactor covers, and solvent extraction column connections in copper, nickel, and cobalt hydrometallurgical circuits. The alloy’s resistance to sulphuric and hydrochloric acid at elevated temperatures and pressures makes it the preferred fastener material for autoclave closure hardware.

Hastelloy B3 Bolts Standards & International Certifications

Hastelloy B3 Bolts from RealBolt Engineering Industries are manufactured to internationally recognised fastener dimensional standards covering thread form, tolerances, strength grades, and quality requirements. Every batch ships with EN 10204 MTC 3.1/3.2, PMI (XRF), NACE MR0175/ISO 15156, and NABL-accredited lab reports — available on request for all orders.
Standards
DIN 931 DIN 933 ISO 4014 ISO 4017 ASME B18.2.1 IS 1364 IS 1367
Certifications
ISO 9001:2015NABL LabPED 2014/68/EUMTC 3.1 / 3.2ASTM F468

Buy Hastelloy B3 Bolts from India's Leading Manufacturer — Get a Competitive Quote Today

Partner with RealBolt — India’s leading manufacturer of certified Hastelloy B3 Bolts — for competitive pricing, EN 10204 MTC 3.1/3.2 documentation, and fast Mumbai dispatch. Standard sizes are ex-stock; custom dimensions accepted with 2–3 week lead time. Request your quote today.
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Answers for Buyers

Hastelloy B3 Bolts — Frequently Asked Questions

Browse expert answers to common questions about Hastelloy B3 Bolts from RealBolt — covering acid corrosion resistance, NACE MR0175 compliance, ASTM standards, available sizes, and MTC documentation. Contact our technical team directly for project-specific guidance on Hastelloy B3 bolts selection and pricing.
Hastelloy B3 hex bolts are manufactured to DIN 931 (metric partial thread), DIN 933 (metric full thread), ISO 4014/4017, and ASME B18.2.1 for inch hex and heavy hex configurations. Stud bolts for flanged connections are supplied per ASME B16.5 (Class 150-2500) and MSS SP-75 for high-pressure applications. Custom thread forms including BSW, BSF, and BSPP are available on request with a 15 working day lead time. All bolts are machined from ASTM B335 UNS N10675 solution-annealed bar with full EN 10204 3.1 MTC.
Hastelloy B3 (UNS N10675) was developed specifically to overcome the limitations of B2 (UNS N10665). The key improvement is the addition of controlled chromium (1.0-3.0%) and tungsten, which suppresses the formation of Ni4Mo precipitates during slow cooling or welding. In practical bolting terms, B3 fasteners can be used in welded assemblies and in equipment that experiences thermal cycling without the risk of intergranular corrosion in the heat-affected zone that made B2 unreliable in fabricated structures. B3 also has a lower carbon ceiling (0.01% max vs 0.02% for B2), further protecting grain boundaries in large-section fasteners.
Hastelloy B3 bolts are rated to approximately 538°C (1000°F) in oxidising environments. In reducing or inert atmospheres – which represent the majority of B3 applications – the alloy can be used at higher temperatures, though mechanical strength decreases progressively above 400°C. For high-temperature oxidising service above 538°C, Hastelloy C276 or Inconel 625 are more appropriate choices. Hastelloy B3’s primary strength is its unmatched resistance to reducing acids at temperatures from ambient up to boiling point, not high-temperature oxidation resistance.
Use a nickel-based anti-seize compound such as Molykote P-37, Jet-Lube KOPR-KOTE Pure Nickel, or Bostik Never-Seez Pure Nickel Special. Apply to the thread flanks and the nut bearing face before assembly. Reduce target torque values by approximately 20% compared to dry assembly values. Never use copper-based or zinc-based anti-seize on Hastelloy B3 – in acid service environments, the galvanic potential difference between copper and the nickel-molybdenum alloy will accelerate crevice corrosion under the nut bearing face, defeating the purpose of specifying a premium alloy fastener.

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