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Hastelloy B3 Nuts Manufacturer & Exporter in India

Explore Hastelloy B3 Nuts 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 Nuts?

Hastelloy B3 nuts are nickel-molybdenum alloy fasteners manufactured 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, sulfuric acid, and other strongly reducing environments across a wide temperature range, including boiling concentrations.

Hastelloy B3 represents a significant advancement over its predecessor B2, incorporating controlled additions of chromium, iron, and tungsten to eliminate the knife-line and heat-affected zone corrosion susceptibility that limited earlier B-series alloys. These nuts are specified for chemical reactor closures, acid storage vessel flanges, and pharmaceutical process equipment where no other commercially available alloy can provide equivalent resistance to reducing acid attack.

Quick Specifications

MaterialHastelloy B3
UNS NumberN10675
DIN Number2.4600
Material StandardASTM B335
Nut Standard (Metric)DIN 934 / DIN 6915 / ISO 4032
Nut Standard (Inch)ASME B18.2.2
Thread FormISO Metric / UNC / UNF
Size 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 Bolts, 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 Bolts
Hastelloy B3 Screws
Hastelloy B3 Washers
Hastelloy B3 Studs
Hastelloy B3 Threaded Rods

Technical Data

Hastelloy B3 Nuts Dimensions, Sizes & Thread Standards

Hastelloy B3 Nuts are available in metric M6–M100 and inch ¼″–4″ as standard. Per DIN 934 (hex nuts) / DIN 6915 (heavy hex) / ISO 4032. Custom thread forms available. Inch dimensions per ASME B18.2.2. All Hastelloy B3 nuts dimensions are verified against applicable DIN, ISO, and ASME B18 standards

Hex Nut Dimensions - Metric (DIN 934 / ISO 4032)

Size (M)Pitch (mm)A/F (mm)Nut Height (mm)A/C (mm)
M61.0105.011.05
M81.25136.514.38
M101.5178.018.90
M121.751910.020.03
M162.02413.026.75
M202.53016.032.95
M243.03619.039.55
M303.54624.050.85
M364.05529.060.79
M424.56534.071.30
M485.07538.082.60
M565.58545.093.56
M646.09551.0104.86
M726.010558.0116.16
M806.011564.0127.46
M1006.014580.0160.00

Dimensional & Material Standards

StandardCoversThread
DIN 934Hex nuts, standard heightMetric
DIN 6915Heavy hex nuts, high-strengthMetric
ISO 4032Hex nuts, style 1Metric
ISO 4033Hex nuts, style 2 (tall)Metric
ASME B18.2.2Hex & heavy hex nutsUNC/UNF
ASME B16.5Heavy hex nuts for flangesUNC
MSS SP-75Heavy hex nuts, high-pressureUNC
Material StandardRequirement
ASTM B335Bar/rod - UNS N10675
ASTM F467Fastener mechanical properties
NACE MR0175Sour service hardness control
EN 10204 3.1Mill test certificate
EN 10204 3.2TPI-witnessed MTC

Material Chemistry

Hastelloy B3 Chemical Composition

Hastelloy B3 Nuts 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 nuts order from RealBolt.

Chemical Composition per ASTM B335

ElementComposition (%)
Nickel (Ni)Balance (min 65%)
Molybdenum (Mo)28.5-31.5%
Chromium (Cr)1.0-3.0%
Iron (Fe)3.0% max
Cobalt (Co)3.0% max
Tungsten (W)3.0% max
Manganese (Mn)3.0% max
Carbon (C)0.01% max
Silicon (Si)0.10% max
Phosphorus (P)0.030% max
Sulfur (S)0.010% max
? All heats verified by NABL-accredited spectrometry. PMI available on request.

Why Hastelloy B3 Alloy Composition Matters for Nuts

Mo (28.5–31.5%) — Reducing Acid Resistance
The ultra-high molybdenum content is the defining characteristic of Hastelloy B3. It provides exceptional resistance to hydrochloric acid at all concentrations and temperatures, including boiling HCl — a condition that destroys virtually every other commercial alloy. Nut threads in contact with acid-wetted bolt shanks benefit directly from this protection.
Low C & Si (0.01% / 0.10% max) — Thermal Stability
The critically low carbon and silicon limits in B3 eliminate the formation of Ni4Mo precipitates that caused stress corrosion cracking in earlier B-series alloys. Hastelloy B3 nuts can be welded into assemblies and used in the as-welded condition without sensitisation or knife-line attack in the heat-affected zone.
Cr + W Additions — Oxidising Upset Tolerance
Small controlled additions of chromium (1–3%) and tungsten (up to 3%) give Hastelloy B3 improved resistance to oxidising upsets — brief excursions into mildly oxidising conditions that would rapidly corrode the older B2 alloy. This makes B3 nuts far more forgiving in real-world process environments where acid purity cannot always be guaranteed.

Fastener Performance

Hastelloy B3 Nuts Mechanical Properties & Torque Reference

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

Proof Load & Torque Reference - Hastelloy B3 Hex Nuts

Nut SizeProof Load (kN)Rec. Torque Dry (Nm)Rec. Torque Lubricated (Nm)
M12288266
M1650195156
M2080390312
M24116675540
M3018413501080
M3626823501880
M4236837503000
M4848455604448
?? 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 B3 Nuts Applications — Industries & End Uses

Hastelloy B3 Nuts 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 nuts application details and RealBolt stock availability.
Hastelloy B3 heavy hex nuts are the standard specification for flange connections on HCl synthesis columns, acid storage tanks, and pickling line headers. The alloy withstands boiling hydrochloric acid at all concentrations – a condition that causes rapid corrosion in stainless steel, titanium, and even Hastelloy C276. Nuts are supplied per ASME B18.2.2 with EN 10204 3.1 MTC.
Hex nuts and heavy hex nuts for reactor vessel closures, heat exchanger channel covers, and pump casing flanges in sulfuric acid concentration units and wet-process phosphoric acid plants. Hastelloy B3 outperforms B2 in these environments due to its improved thermal stability and resistance to oxidising upsets during process excursions.
Flange nut sets for glass-lined reactor nozzle connections, agitator seal housings, and condenser flanges in pharmaceutical API synthesis where halogenated solvents, acetic acid, and mixed reducing acid streams are processed. B3 nuts eliminate the risk of metallic contamination from corrosion products that would compromise product purity.
Hastelloy B3 nuts are specified for acetic acid plant column flanges, reboiler connections, and overhead condenser nozzles where glacial acetic acid and acetic anhydride at elevated temperatures attack standard austenitic stainless steel and even Hastelloy C276 at unacceptable corrosion rates.

Hastelloy B3 Nuts Standards & International Certifications

Hastelloy B3 Nuts 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 934 ISO 4032 ASME B18.2.2 IS 1364 IS 1367
Certifications
ISO 9001:2015NACE MR0175NABL LabPED 2014/68/EUMTC 3.1 / 3.2

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

Partner with RealBolt — India’s leading manufacturer of certified Hastelloy B3 Nuts — 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 Nuts — Frequently Asked Questions

Browse expert answers to common questions about Hastelloy B3 Nuts 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 nuts selection and pricing.
Hastelloy B3 hex nuts are manufactured to DIN 934 (standard hex, metric), DIN 6915 (heavy hex, metric), ISO 4032 (style 1) and ISO 4033 (style 2 tall), and ASME B18.2.2 for inch heavy hex nuts used in ASME B16.5 flange assemblies. Coupling nuts, lock nuts, and flange nuts are available on request. Custom thread forms including BSW, BSF, and BSPP can be produced with a 15 working day lead time. All nuts are supplied with EN 10204 3.1 mill test certificates as standard.
This combination is not recommended for immersed acid service. Hastelloy B3 and austenitic stainless steel have a measurable galvanic potential difference in reducing acid electrolytes, which can accelerate corrosion of the less noble stainless steel bolt. For full system integrity in HCl or H2SO4 service, the complete fastener assembly – studs or bolts, nuts, and washers – should be specified in Hastelloy B3 UNS N10675. Contact our engineering team for matched-heat flange bolt sets.
Hastelloy B3 nuts perform reliably in reducing acid environments up to approximately 538°C. However, the alloy’s primary design intent is corrosion resistance in reducing media rather than high-temperature oxidising service. Above 538°C in oxidising atmospheres, alloys with higher chromium content such as Hastelloy C22 or Inconel 625 are more appropriate. For boiling HCl and concentrated H2SO4 at process temperatures below 200°C, Hastelloy B3 remains the benchmark alloy with no commercially available equivalent.
Hastelloy B3 nuts can be supplied with hardness controlled to 35 HRC maximum per NACE MR0175 / ISO 15156 requirements. However, B3 is primarily selected for its resistance to reducing acids rather than H2S sour service. For dedicated sour service applications, Hastelloy C276 or Inconel 625 are more commonly specified and have broader operator qualification histories under Shell DEP and ExxonMobil EMSP. Our engineering team can advise on the most appropriate alloy for your specific H2S partial pressure and chloride concentration.

Industrial Cities We Serve:

  • Ahmedabad
  • Aurangabad
  • Bengaluru
  • Chennai
  • Coimbatore
  • Faridabad
  • Gandhidham
  • Greater Noida
  • Gurugram
  • Hazira
  • Hosur
  • Hyderabad
  • Jamnagar
  • Jamshedpur
  • Ludhiana
  • Mumbai
  • Mundra
  • Mysuru
  • Nagpur
  • Nashik
  • Navi Mumbai
  • Noida
  • Pune
  • Rajkot
  • Sanand
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  • Tiruppur
  • Vadodara
  • Visakhapatnam

Countries We Export To:

  • US
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  • Germany
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