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EN 24 (4340 Equiv.) Studs Manufacturer & Exporter in India

Explore EN 24 (4340 Equiv.) Studs Manufacturer & Exporter in India manufactured for demanding industrial applications with reliable strength, corrosion resistance and compliance with international standards.
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-196

Min Temp

870

Max Temp

🌡

870

Suitable for continuous service up to approximately 870°C under typical operating conditions.

⚡

620

Typical tensile strength around 620 MPa depending on product form and heat treatment.

🛡

Very Good

Very Good corrosion resistance in a wide range of industrial environments.

⚖

8

Typical density is approximately 8.0 g/cm³.

Product Overview

What are EN 24 (4340 Equiv.) Studs?

EN 24 (4340 Equiv.) studs are high-strength alloy steel fasteners manufactured from EN 24 (AISI 4340 equivalent) bar stock, renowned for their exceptional toughness, fatigue resistance, and high tensile strength. These studs are typically supplied in the quenched and tempered condition, achieving tensile strengths up to 1080 MPa and above, making them ideal for demanding mechanical and structural applications.

EN 24 (4340) alloy steel contains nickel, chromium, and molybdenum, providing a unique combination of strength, ductility, and hardenability. EN 24 studs are widely specified for critical bolted joints in heavy engineering, power generation, oil & gas, and automotive sectors where superior mechanical performance and reliability are essential.

Quick Specifications

MaterialEN 24 (AISI 4340 Equivalent)
UNS NumberG43400
DIN Number1.6511
Material StandardBS 970-3:1991 / ASTM A193 Grade B7 (4340)
Stud Standard (Metric)DIN 976 / ISO 898-1
Stud Standard (Inch)ASME B16.5 / ASTM A193
Thread FormISO Metric / UNC / UNF
Diameter RangeM8-M100 / ?"-4"
Tensile Strength930-1080 MPa (135-157 ksi)
Yield Strength785 MPa (114 ksi) min
Hardness28-36 HRC
? All material certified by NABL-accredited laboratory. Heat treatment charts and mechanical test reports available on request.

Complete the Fastener Set

Other EN 24 (4340 Equiv.) Fastener Products Available from RealBolt

RealBolt also manufactures the complete EN 24 (4340 Equiv.) fastener range — EN 24 (4340 Equiv.) Bolts, EN 24 (4340 Equiv.) Nuts, EN 24 (4340 Equiv.) Screws, EN 24 (4340 Equiv.) Washers, EN 24 (4340 Equiv.) Threaded Rods — from certified bar stock per ASTM with full EN 10204 MTC 3.1/3.2 documentation and fast Mumbai dispatch.
EN 24 (4340 Equiv.) Bolts
EN 24 (4340 Equiv.) Nuts
EN 24 (4340 Equiv.) Screws
EN 24 (4340 Equiv.) Washers
EN 24 (4340 Equiv.) Threaded Rods

Technical Data

EN 24 (4340 Equiv.) Studs Dimensions, Sizes & Thread Standards

EN 24 (4340 Equiv.) Studs are available in metric M6–M100 and inch ¼″–4″ as standard. Per DIN 976 (full thread) / ISO 898-1. Custom cut lengths available in 5mm increments. Inch dimensions per ASME B16.5 and ASTM A193. All EN 24 (4340 Equiv.) studs dimensions conform to applicable DIN, ISO, and ASME B18 standards.

Stud Dimensions - Metric (DIN 976 / ISO 898-1)

Size (M)Pitch (mm)Thread Length (mm)Min L (mm)Max L (mm)
M81.25Full20500
M101.5Full25600
M121.75Full30800
M162.0Full351000
M202.5Full401200
M243.0Full501500
M303.5Full602000
M364.0Full702500
M424.5Full803000
M485.0Full1003500
M565.5Full1204000
M646.0Full1404500
M726.0Full1605000
M806.0Full1806000
M1006.0Full2007000

Dimensional & Material Standards

StandardCoversThread
DIN 976Threaded rods & studsMetric
ISO 898-1Mechanical propertiesMetric
ASME B16.5Stud bolts for flangesUNC
ASTM A193Alloy steel studsUNC/UNF
BS 4882Petrochemical boltingMetric/UNC
Material StandardRequirement
BS 970-3:1991EN 24 bar/rod
ASTM A3224340 bar/rod
ASTM A193 B7Heat treated studs
EN 10204 3.1Mill test certificate
EN 10204 3.2TPI-witnessed MTC

Material Chemistry

EN 24 (4340 Equiv.) Chemical Composition

EN 24 (4340 Equiv.) Studs are produced from medium-carbon or alloy steel with carbon (0.15–0.55%), chromium, manganese, and boron additions controlled per ASTM and ISO 898-1. Carbon content and quench-and-temper heat treatment are the primary strength levers, delivering proof loads from 580 MPa (Class 8.8) to 970 MPa (Class 12.9).

Chemical Composition per BS 970-3:1991 / ASTM A322

ElementComposition (%)
Carbon (C)0.36-0.44
Silicon (Si)0.10-0.35
Manganese (Mn)0.45-0.70
Nickel (Ni)1.30-1.80
Chromium (Cr)0.50-1.00
Molybdenum (Mo)0.15-0.30
Sulphur (S)0.035 max
Phosphorus (P)0.035 max
? All heats verified by NABL-accredited spectrometry. Full chemical test reports supplied with every batch.

Why EN 24 (4340 Equiv.) Alloy Composition Matters for Studs

Ni (1.3–1.8%) — Toughness & Hardenability
Nickel content ensures deep hardenability and high impact strength, making EN 24 studs reliable for dynamic and shock-loaded joints.
Cr (0.5–1.0%) — Wear & Corrosion Resistance
Chromium improves surface hardness and provides moderate corrosion resistance, extending stud life in aggressive environments.
Mo (0.15–0.30%) — Creep & Fatigue Strength
Molybdenum enhances high-temperature strength and fatigue resistance, critical for power plant and heavy machinery bolting.

Fastener Performance

EN 24 (4340 Equiv.) Studs Mechanical Properties & Torque Reference

The table below lists mechanical properties and torque reference for EN 24 (4340 Equiv.) Studs per ASTM. EN 24 (4340 Equiv.) studs achieve 620 MPa tensile strength, with hardness, yield, and elongation values verified by NABL-accredited testing and reported in the EN 10204 MTC.

Stud SizeDry (Nm)Lubricated (Nm)Clamp Load (kN)
M121108838
M1627021678
M20540432122
M24930744176
M3018501480285
M3632002560410
M4251004080570
M4876006080750
?? Anti-galling: Use molybdenum-based or graphite anti-seize. Lubricated values assume K=0.16. Avoid copper-based anti-seize for high-temperature or hydrogen service.

Industry Applications

EN 24 (4340 Equiv.) Studs Applications — Industries & End Uses

EN 24 (4340 Equiv.) Studs from RealBolt are specified across structural engineering, automotive, machinery, and pressure vessels where very good corrosion resistance and 620 MPa tensile strength are required for reliable fastener performance. Click each industry below for detailed application examples.
EN 24 (4340 Equiv.) studs are widely used for turbine casing joints, boiler drum connections, and high-pressure steam piping in thermal and combined cycle power plants. Their high strength and toughness ensure reliable performance under cyclic loading and elevated temperatures.
These studs are specified for ASME B16.5/B16.47 flange joints, pressure vessel closures, and pipeline connections in refineries and petrochemical plants. EN 24’s mechanical properties make it ideal for critical bolting in sour and non-sour service.
EN 24 (4340) studs are used in mining crushers, mill liners, and heavy machinery where shock loading and fatigue resistance are essential. Their deep hardenability ensures consistent strength throughout large diameter studs.
High-performance engine head studs, crankshaft main bearing studs, and drivetrain fasteners in motorsport and commercial vehicles rely on EN 24 for its superior fatigue and tensile strength.

EN 24 (4340 Equiv.) Studs Standards & International Certifications

EN 24 (4340 Equiv.) Studs 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, hardness test certificate, dimensional inspection report, and proof load test records — available on request for all orders.
Standards
DIN 938 DIN 939 DIN 976-1 ASME B18.31.2 IS 1364 IS 1367 SAE J429
Certifications
ISO 9001:2015PED 2014/68/EUNABL LabMTC 3.1 / 3.2

Buy EN 24 (4340 Equiv.) Studs from India's Leading Manufacturer — Get a Competitive Quote Today

Partner with RealBolt — India’s leading manufacturer of certified EN 24 (4340 Equiv.) Studs — 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

EN 24 (4340 Equiv.) Studs — Frequently Asked Questions

Browse expert answers to common questions about EN 24 (4340 Equiv.) Studs from RealBolt — covering property class, tensile and proof load, galvanizing embrittlement risk, surface finishes, and dimensional certification. Contact our technical team directly for project-specific guidance on EN 24 (4340 Equiv.) studs selection and pricing.
EN 24 (4340 Equiv.) studs are manufactured to DIN 976 (metric full thread), ISO 898-1 (mechanical properties), ASME B16.5 (flange studs), and ASTM A193 Grade B7 (inch series). Custom thread forms (UNC, UNF, BSW, BSF) and cut lengths are available on request with short lead times.
Use a molybdenum-based or graphite anti-seize compound (such as Molykote 1000 or Loctite LB 8008) on threads and nut faces. For high-temperature or hydrogen service, avoid copper-based anti-seize. Lubricated torque values should be reduced by 20% compared to dry assembly.
Yes – EN 24 (4340) studs maintain high strength up to 450°C and are widely used in turbine, boiler, and pressure vessel bolting. For continuous service above 450°C, consult engineering for alternative grades. All studs are supplied with heat treatment charts and hardness survey.
No MOQ for standard sizes (M12-M36) held in stock – we supply from single pieces for urgent maintenance. Custom diameters and cut lengths have an MOQ of 10 kg. Flange stud sets are supplied as per project requirement with no minimum. Quantity discounts at 50, 200, and 500 pieces.

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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  • Qatar
  • Oman
  • Kuwait
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