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Inconel 625 Bolts Manufacturer & Exporter in India

Explore Inconel 625 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

1200

Max Temp

🌡

1200

Suitable for continuous service up to approximately 1200°C under typical operating conditions.

⚡

760

Typical tensile strength around 760 MPa depending on product form and heat treatment.

🛡

Excellent

Excellent corrosion resistance in a wide range of industrial environments.

⚖

8.4

Typical density is approximately 8.4 g/cm³.

Product Overview

What are Inconel 625 Bolts?

Inconel 625 bolts are high-performance nickel-chromium-molybdenum fasteners machined from UNS N06625 bar stock conforming to ASTM B446. The alloy derives its exceptional strength through solid-solution hardening by molybdenum (8-10%) and niobium (3.15-4.15%), achieving a minimum tensile strength of 758 MPa in the annealed condition without any precipitation hardening treatment.

With a PREN exceeding 51, Inconel 625 bolts resist chloride pitting, crevice corrosion, and stress corrosion cracking in seawater environments where standard austenitic stainless steels fail rapidly. These fasteners are specified under NACE MR0175/ISO 15156 for sour-service flanged connections, subsea wellhead assemblies, offshore structural joints, and high-temperature chemical process equipment worldwide.

Quick Specifications

MaterialInconel 625
UNS NumberN06625
DIN Number2.4856
Material StandardASTM B446
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 Strength758 MPa (110 ksi) min
Yield Strength414 MPa (60 ksi) min
HardnessMax 35 HRC / 220 HB
? All material certified by NABL-accredited laboratory. PMI available on request.

Complete the Fastener Set

Other Inconel 625 Fastener Products Available from RealBolt

RealBolt also manufactures the complete Inconel 625 fastener range from certified nickel-chromium superalloy bar stock, including Inconel 625 Nuts, Inconel 625 Screws, Inconel 625 Washers, Inconel 625 Studs, and Inconel 625 Threaded Rods. All Inconel 625 fastener types are produced to ASTM with full EN 10204 MTC 3.1/3.2 documentation.
Inconel 625 Nuts
Inconel 625 Screws
Inconel 625 Washers
Inconel 625 Studs
Inconel 625 Threaded Rods

Technical Data

Inconel 625 Bolts Dimensions, Sizes & Thread Standards

Inconel 625 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 available in 5 mm increments. Inch dimensions supplied per ASME B18.2.1. All Inconel 625 bolts dimensions conform to applicable DIN, ISO, and ASME B18 standards.

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, partial threadMetric
ISO 4017Hex head screws, full threadMetric
ASME B18.2.1Hex and heavy hex boltsUNC/UNF
ASME B16.5Stud bolts for flangesUNC
MSS SP-75Stud bolts, high-pressure fittingsUNC
Material StandardRequirement
ASTM B446Bar and rod - UNS N06625
ASTM F468Fastener mechanical properties
NACE MR0175Sour service hardness =35 HRC
EN 10204 3.1Mill test certificate
EN 10204 3.2TPI-witnessed mill test certificate

Material Chemistry

Inconel 625 Chemical Composition

Inconel 625 Bolts are manufactured from a nickel-chromium superalloy containing nickel (72% min), chromium (14–17%), and iron (6–10%). Each element is precisely controlled per ASTM — nickel provides chloride SCC immunity, chromium drives high-temperature oxidation resistance, and iron balances structural stability and alloy cost.

Chemical Composition per ASTM B446

ElementComposition (%)
Nickel (Ni)58.0% min
Chromium (Cr)20.0-23.0%
Molybdenum (Mo)8.0-10.0%
Niobium + Tantalum (Nb+Ta)3.15-4.15%
Iron (Fe)5.0% max
Carbon (C)0.10% max
Manganese (Mn)0.50% max
Silicon (Si)0.50% max
Aluminium (Al)0.40% max
Cobalt (Co)1.0% max
Phosphorus (P)0.015% max
Sulphur (S)0.015% max
? All heats verified by NABL-accredited optical emission spectrometry. PMI testing available on request.

Why Inconel 625 Alloy Composition Matters for Bolts

Mo (8–10%) — Superior Pitting and Crevice Corrosion Resistance
The high molybdenum content pushes the PREN above 51, making Inconel 625 bolts completely immune to crevice corrosion beneath bolt heads, under washers, and within threaded engagement zones in seawater and chloride-bearing process fluids.
Nb+Ta (3.15–4.15%) — Grain Boundary Stabilisation
Niobium and tantalum tie up carbon at grain boundaries, preventing sensitisation during welding or elevated-temperature service. Inconel 625 bolts retain full corrosion resistance in heat-affected zones without requiring post-weld heat treatment.
Solid-Solution Strengthening — No Age Hardening Required
Unlike age-hardened alloys such as Inconel 718, alloy 625 achieves its 758 MPa tensile strength entirely through solid-solution mechanisms. This eliminates the risk of over-ageing embrittlement in service and simplifies fastener manufacturing quality control significantly.

Fastener Performance

Inconel 625 Bolts Mechanical Properties & Torque Reference

The table below lists mechanical properties and torque reference for Inconel 625 Bolts per ASTM. Inconel 625 bolts achieve 760 MPa tensile strength, with hardness, yield, and elongation values verified by NABL-accredited testing and reported in the EN 10204 MTC.

Tightening Torque Reference - Inconel 625 Bolts

Bolt SizeDry (Nm)Lubricated (Nm)Clamp Load (kN)
M12907233
M1621517279
M20425340125
M24740592181
M3014801184287
M3625702056416
M4241003280572
M4860804864751
?? Anti-galling notice: Always apply nickel-based anti-seize (Molykote P-37 or equivalent) to threads and bearing faces. Lubricated values assume friction coefficient K=0.15. Never use copper-based or zinc-based anti-seize on nickel alloy fasteners - galvanic corrosion risk.

Industry Applications

Inconel 625 Bolts Applications — Industries & End Uses

Inconel 625 Bolts from RealBolt are specified across oil and gas, aerospace, chemical processing, and power generation where excellent corrosion resistance and 760 MPa tensile strength are required for reliable fastener performance. Click each industry below for detailed application examples.
Inconel 625 stud bolts and hex bolts are the standard specification for ASME B16.5 and B16.47 flanged wellhead connections, blowout preventer stacks, and subsea Christmas tree assemblies. Fully compliant with NACE MR0175/ISO 15156 for H2S sour service. Listed in Shell DEP and ExxonMobil EMSP approved materials registers.
Hex bolts, flange bolts, and socket head cap screws in Inconel 625 are specified for offshore platform structural connections, splash-zone pipe supports, marine heat exchanger channel covers, and propeller shaft coupling flanges where PREN 51+ is required for long-term seawater immersion without pitting or crevice corrosion beneath bolt heads.
Flange stud bolt sets for chemical reactor closures, TEMA Class B and C heat exchanger channel covers, and pressure vessel nozzle connections in phosphoric acid, hydrofluoric acid, organic acid, and mixed halide process streams where SS 316L and duplex stainless steels are inadequate for the corrosion duty.
Inconel 625 bolts are used in aircraft exhaust system flanges, thrust reverser structural attachments, nacelle firewall connections, and military gas turbine casings where simultaneous oxidation resistance to 980°C, high fatigue strength, and low magnetic permeability are required. Manufactured to AMS 5666 specification on request.

Inconel 625 Bolts Standards & International Certifications

Inconel 625 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 Accredited LabPED 2014/68/EUMTC 3.1 / 3.2AMS 5666

Buy Inconel 625 Bolts from India's Leading Manufacturer — Get a Competitive Quote Today

Partner with RealBolt — India’s leading manufacturer of certified Inconel 625 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

Inconel 625 Bolts — Frequently Asked Questions

Browse expert answers to common questions about Inconel 625 Bolts from RealBolt — covering ASTM standards, max service temperature, corrosion resistance, available sizes, lead times, and MTC certification. Contact our technical team directly for project-specific guidance on Inconel 625 bolts selection and pricing.
Inconel 625 bolts are manufactured to DIN 931 (metric hex bolt, partial thread), DIN 933 (metric hex bolt, full thread), ISO 4014 and ISO 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. Non-standard thread forms including BSW, BSF, and BSPP are available on request with a typical lead time of 15 working days from order confirmation.
Both alloys offer outstanding corrosion resistance, but they suit different environments. Inconel 625 (UNS N06625) provides excellent resistance to seawater, oxidising acids, and high-temperature oxidation up to 980°C, making it the preferred choice for offshore, marine, and high-temperature process bolting. Hastelloy C276 (UNS N10276) offers superior resistance to reducing acids, mixed acid environments, and wet chlorine gas due to its higher molybdenum content of 15-17%. For most offshore and subsea flange bolting applications, Inconel 625 is the cost-effective and technically correct specification. Contact our engineering team if you need a side-by-side corrosion assessment for your specific process fluid.
Yes. Inconel 625 bolts supplied in the annealed condition with hardness not exceeding 35 HRC (220 HB) fully comply with NACE MR0175/ISO 15156-3 for use in H2S-containing sour service environments. Each batch is supplied with a hardness survey report confirming compliance. For critical sour service applications such as wellhead flanges and BOP connections, we can supply individual piece hardness certification on request at no additional charge.
In oxidising atmospheres, Inconel 625 bolts maintain structural integrity and oxidation resistance up to 980°C. In reducing or sulphidising atmospheres the practical limit is lower, typically 650-700°C, depending on the specific gas composition. For cyclic thermal applications such as HRSG ducting and FGD scrubber flanges, the alloy’s low thermal expansion coefficient of 12.8 µm/m·°C minimises differential expansion stresses at bolted joints during heat-up and cool-down cycles, significantly extending joint service life compared to austenitic stainless steel bolting.

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  • Ahmedabad
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