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Hastelloy B2 Bolts Manufacturer & Exporter in India

Explore Hastelloy B2 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 B2 Bolts?

Hastelloy B2 bolts are nickel-molybdenum alloy fasteners manufactured from UNS N10665 bar stock conforming to ASTM B335. The alloy’s exceptionally high molybdenum content (26-30%) delivers outstanding resistance to reducing acids – particularly hydrochloric acid at all concentrations and temperatures – making it one of the most chemically aggressive-environment fastener materials available.

Hastelloy B2 bolts provide a minimum tensile strength of 760 MPa in the annealed condition through solid-solution strengthening. The alloy is specified for reactor closures, heat exchanger flanges, and chemical process piping where hydrochloric, sulfuric, and phosphoric acid environments would rapidly destroy stainless steel or even other nickel alloys. Low carbon and silicon content minimises grain boundary carbide precipitation, preserving corrosion resistance in the heat-affected zone of welded assemblies.

Quick Specifications

MaterialHastelloy B2
UNS NumberN10665
DIN Number2.4617
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 B2 Fastener Products Available from RealBolt

RealBolt also manufactures the complete Hastelloy B2 fastener range from certified nickel-molybdenum-chromium superalloy bar stock, including Hastelloy B2 Nuts, Hastelloy B2 Screws, Hastelloy B2 Washers, Hastelloy B2 Studs, and Hastelloy B2 Threaded Rods. All Hastelloy B2 fastener types are produced to ASTM with full EN 10204 MTC 3.1/3.2 documentation.
Hastelloy B2 Nuts
Hastelloy B2 Screws
Hastelloy B2 Washers
Hastelloy B2 Studs
Hastelloy B2 Threaded Rods

Technical Data

Hastelloy B2 Bolts Dimensions, Sizes & Thread Standards

Hastelloy B2 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 B2 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 N10665
ASTM B333Plate/sheet - UNS N10665
ASTM F468Fastener mechanical properties
NACE MR0175Sour service =35 HRC
EN 10204 3.1Mill test certificate
EN 10204 3.2TPI-witnessed MTC

Material Chemistry

Hastelloy B2 Chemical Composition

Hastelloy B2 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 B2 bolts order from RealBolt.

Chemical Composition per ASTM B335

ElementComposition (%)
Nickel (Ni)Balance (min 65%)
Molybdenum (Mo)26.0-30.0%
Iron (Fe)2.0% max
Chromium (Cr)1.0% max
Carbon (C)0.02% max
Silicon (Si)0.10% max
Manganese (Mn)1.0% max
Cobalt (Co)1.0% max
Phosphorus (P)0.04% max
Sulfur (S)0.03% max
? All heats verified by NABL-accredited spectrometry. PMI available on request.

Why Hastelloy B2 Alloy Composition Matters for Bolts

Mo (26–30%) — Unmatched Reducing Acid Resistance
The ultra-high molybdenum content is the defining characteristic of Hastelloy B2. It provides exceptional resistance to hydrochloric acid at all concentrations up to the boiling point — a performance level no other commercially available alloy can match. This makes B2 bolts the default specification for HCl reactor and distillation column flanges.
Ultra-Low C & Si — Grain Boundary Stability
Carbon is held to 0.02% max and silicon to 0.10% max. These ultra-low levels prevent the formation of molybdenum-rich carbide and silicide precipitates at grain boundaries during fabrication and welding, which were the primary cause of intergranular corrosion failures in the predecessor alloy Hastelloy B. B2 bolts retain full corrosion resistance in the as-welded condition.
Nickel-Dominant Matrix — Structural Integrity in Reducing Environments
The nickel-dominant matrix (65% min) provides the ductility and toughness needed for reliable bolt preload retention under thermal cycling. Unlike iron-based alloys, the Ni-Mo matrix does not embrittle in concentrated reducing acid service, ensuring consistent clamping force throughout the service life of the joint.

Fastener Performance

Hastelloy B2 Bolts Mechanical Properties & Torque Reference

The table below lists mechanical properties and torque reference for Hastelloy B2 Bolts per ASTM. Hastelloy B2 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 B2 Hex Bolts

Bolt SizeDry (Nm)Lubricated (Nm)Clamp Load (kN)
M12856830
M1620516474
M20410328118
M24710568172
M3014201136274
M3624801984398
M4239603168548
M4858804704720
?? 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 service.

Industry Applications

Hastelloy B2 Bolts Applications — Industries & End Uses

Hastelloy B2 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 B2 bolts application details and RealBolt stock availability.
Hastelloy B2 stud bolts and hex bolts are the primary specification for flanged closures on HCl synthesis reactors, hydrochloric acid distillation columns, and acid storage tank nozzle connections. The alloy withstands HCl at all concentrations up to the boiling point – a condition that destroys all grades of stainless steel and most other nickel alloys within weeks.
Flange bolt sets for sulfuric acid concentrators, phosphoric acid evaporators, and acetic acid process piping where reducing acid conditions prevail. Hastelloy B2 bolts outperform Hastelloy C276 in pure reducing acid environments due to the absence of chromium, which can accelerate corrosion under strongly reducing conditions.
Hex bolts and socket head cap screws for reactor vessel closures, agitator shaft flanges, and heat exchanger covers in pharmaceutical API synthesis plants where halogenated solvents, reducing acids, and stringent contamination control requirements demand a high-purity, corrosion-immune fastener material.
Flange stud bolt sets for chlorine dioxide bleaching equipment, HCl wash stage piping, and acid filtrate pump flanges in kraft pulp mills. Hastelloy B2 bolts resist the combined attack of hydrochloric acid and chlorine compounds that cause rapid stress corrosion cracking in austenitic stainless steel bolting.

Hastelloy B2 Bolts Standards & International Certifications

Hastelloy B2 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 9001:2015NACE MR0175NABL LabPED 2014/68/EUMTC 3.1 / 3.2

Buy Hastelloy B2 Bolts from India's Leading Manufacturer — Get a Competitive Quote Today

Partner with RealBolt — India’s leading manufacturer of certified Hastelloy B2 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 B2 Bolts — Frequently Asked Questions

Browse expert answers to common questions about Hastelloy B2 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 B2 bolts selection and pricing.
Hastelloy B2 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 produced per ASME B16.5 and MSS SP-75. Custom thread forms including BSW, BSF, and BSPP are available on request with a standard lead time of 15 working days. All fasteners are supplied with EN 10204 3.1 mill test certificates as standard.
Yes – Hastelloy B2 is specifically engineered for hydrochloric acid service. It provides complete resistance to HCl at all concentrations from dilute to concentrated, including at or near the boiling point. This performance is unmatched by any grade of stainless steel and surpasses most other nickel alloys in purely reducing acid environments. Hastelloy B2 bolts are routinely specified for HCl reactor flanges, distillation column closures, and acid storage nozzle connections operating continuously at temperatures up to 120°C in concentrated HCl.
Always use a nickel-based anti-seize compound such as Molykote P-37, Jet-Lube KOPR-KOTE Pure Nickel, or Bostik Never-Seez Pure Nickel. Apply the compound to the bolt threads and the nut bearing face before assembly. Reduce target torque values by approximately 20% compared to dry assembly values. Copper-based and zinc-based anti-seize compounds must never be used on Hastelloy B2 or any nickel-molybdenum alloy – the galvanic potential difference between copper or zinc and the nickel matrix accelerates corrosion, particularly in acid service environments.
No – this is a critical application limitation. Hastelloy B2 is designed exclusively for reducing acid environments. In oxidising acids such as nitric acid, or in mixed acid systems containing oxidising agents (ferric chloride, cupric chloride, dissolved oxygen), the alloy’s corrosion resistance drops sharply. For oxidising or mixed acid service, Hastelloy C276 (UNS N10276) or Hastelloy C22 (UNS N06022) bolts should be specified instead. Always confirm the oxidising or reducing nature of the process fluid before selecting B2 fasteners.

Industrial Cities We Serve:

  • Ahmedabad
  • Aurangabad
  • Bengaluru
  • Chennai
  • Coimbatore
  • Faridabad
  • Gandhidham
  • Greater Noida
  • Gurugram
  • Hazira
  • Hosur
  • Hyderabad
  • Jamnagar
  • Jamshedpur
  • Ludhiana
  • Mumbai
  • Mundra
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  • Nagpur
  • Nashik
  • Navi Mumbai
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  • US
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