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

Explore EN 24 (4340 Equiv.) Bolts 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.) Bolts?

EN 24 (4340 Equivalent) bolts are high-strength alloy steel fasteners manufactured from EN 24 (AISI 4340) bar stock, a nickel-chromium-molybdenum steel renowned for its exceptional toughness, fatigue resistance, and high tensile strength. These bolts 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 bolts are widely specified in heavy engineering, automotive, aerospace, and oil & gas sectors where superior mechanical properties and resistance to shock loading are critical. They conform to international standards such as ASTM A193 Grade B7 (for equivalent chemistry and properties), BS 970-3, and DIN 17200, ensuring reliable performance in high-stress environments.

Quick Specifications

MaterialEN 24 (AISI 4340)
UNS NumberG43400
DIN Number1.6511
Material StandardBS 970-3:1991 / ASTM A322
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 Strength850-1080 MPa (123-157 ksi)
Yield Strength680 MPa (99 ksi) min
Hardness28-36 HRC
? All material certified by NABL-accredited laboratory. Ultrasonic and MPI testing 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.) Nuts, EN 24 (4340 Equiv.) Screws, EN 24 (4340 Equiv.) Washers, EN 24 (4340 Equiv.) Studs, 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.) Nuts
EN 24 (4340 Equiv.) Screws
EN 24 (4340 Equiv.) Washers
EN 24 (4340 Equiv.) Studs
EN 24 (4340 Equiv.) Threaded Rods

Technical Data

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

EN 24 (4340 Equiv.) 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 EN 24 (4340 Equiv.) 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, partialMetric
ISO 4017Hex head screws, fullMetric
ASME B18.2.1Hex & heavy hex boltsUNC/UNF
ASME B16.5Stud bolts for flangesUNC
BS 3692Precision hex boltsMetric
Material StandardRequirement
BS 970-3:1991EN 24 bar/rod
ASTM A3224340 bar/rod
ASTM A193 B7Mechanical properties
EN 10204 3.1Mill test certificate
EN 10204 3.2TPI-witnessed MTC

Material Chemistry

EN 24 (4340 Equiv.) Chemical Composition

EN 24 (4340 Equiv.) Bolts 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)0.90-1.40
Molybdenum (Mo)0.20-0.35
Sulphur (S)0.035 max
Phosphorus (P)0.035 max
Iron (Fe)Balance
? All heats verified by NABL-accredited spectrometry. PMI and mechanical testing available on request.

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

Ni-Cr-Mo Alloying — High Strength & Toughness
The combination of nickel, chromium, and molybdenum in EN 24 (4340) provides outstanding tensile strength, ductility, and impact resistance, making these bolts ideal for dynamic and shock-loaded applications.
Through-Hardening Capability
EN 24 bolts can be heat treated to achieve uniform hardness throughout the cross-section, ensuring reliable performance in large diameters and critical joints.
Fatigue & Wear Resistance
The alloy’s balanced composition delivers excellent fatigue life and resistance to surface wear, essential for high-cycle bolted connections in automotive, aerospace, and heavy machinery.

Fastener Performance

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

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

Bolt SizeDry (Nm)Lubricated (Nm)Clamp Load (kN)
M121108838
M1627021680
M20540432125
M24930744180
M3018501480295
M3632002560425
M4251004080590
M4876006080780
?? Anti-galling: Use molybdenum-based anti-seize for EN 24 bolts. Lubricated values assume K=0.16. Avoid copper-based anti-seize in corrosive environments.

Industry Applications

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

EN 24 (4340 Equiv.) Bolts 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.) bolts are widely used in heavy-duty machinery, press frames, and forging equipment where high tensile strength and shock resistance are essential for bolted joints subjected to dynamic loads and vibration.
Critical fasteners for crankshafts, connecting rods, suspension arms, and drivetrain assemblies in performance vehicles and motorsport, where fatigue resistance and reliability under cyclic loading are paramount.
Stud bolts and hex bolts for API flanges, BOP stacks, and high-pressure vessel closures in drilling rigs and wellhead assemblies, offering superior strength and toughness in harsh field conditions.
EN 24 bolts are specified for landing gear, actuator assemblies, and structural joints in aircraft and military vehicles, where high strength-to-weight ratio and impact resistance are required.

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

EN 24 (4340 Equiv.) 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, hardness test certificate, dimensional inspection report, and proof load test records — available on request for all orders.
Standards
DIN 931 DIN 933 DIN 960 DIN 961 DIN 6914 ISO 4014 ISO 4017 ISO 8676 ISO 8765 ASME B18.2.1 EN 14399 EN 15048 EN ISO 4014 EN ISO 4017 BS EN ISO 4014 BS 3692 BS 4190 IS 1363 IS 1364 IS 3757 SAE J429 UNI 5737 UNI 5739 CSN 021101 PN 82101
Certifications
ISO 9001:2015PED 2014/68/EUNABL LabMTC 3.1 / 3.2

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

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

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

Browse expert answers to common questions about EN 24 (4340 Equiv.) Bolts 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.) bolts selection and pricing.
EN 24 (4340 Equiv.) bolts are available to DIN 931 (metric partial thread), DIN 933 (metric full thread), ISO 4014/4017, and ASME B18.2.1 (inch hex and heavy hex). Stud bolts for flanges are supplied per ASME B16.5 and BS 3692. Custom thread forms (UNC, UNF, BSW, BSF) are available on request with short lead times.
Molybdenum-based anti-seize compound (such as Molykote 1000 or Loctite LB 8012) is recommended for EN 24 bolts, especially in high-load or high-temperature applications. Apply to threads and bearing surfaces. Avoid copper-based anti-seize in corrosive or hydrogen sulfide environments.
EN 24 (4340 Equiv.) bolts are suitable for continuous service up to 450°C. For higher temperatures, consult for alternative grades such as alloy 660 or Inconel 718. Always verify mechanical properties at operating temperature for critical applications.
No formal MOQ for standard sizes (M12-M36) held in stock – single-piece supply available for urgent needs. Custom sizes or special heat treatments may require a 10 kg minimum. Quantity discounts apply 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
  • Surat
  • Thane
  • Tiruppur
  • Vadodara
  • Visakhapatnam

Countries We Export To:

  • US
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  • Mexico
  • Germany
  • UK
  • France
  • Italy
  • Spain
  • Netherlands
  • Belgium
  • Poland
  • Sweden
  • Norway
  • Denmark
  • Turkey
  • UAE
  • Saudi Arabia
  • Qatar
  • Oman
  • Kuwait
  • Bahrain
  • South Africa
  • Egypt
  • Nigeria
  • Australia
  • New Zealand
  • Singapore
  • Malaysia
  • Indonesia
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