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

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

EN 24 (4340 Equivalent) screws 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 screws 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 screws are widely specified in aerospace, automotive, and heavy engineering sectors for critical bolted joints subjected to high loads, impact, and cyclic stresses. The alloy’s balanced composition ensures excellent machinability, through-hardening capability, and reliable performance in both ambient and elevated temperature environments.

Quick Specifications

MaterialEN 24 (AISI 4340) Alloy Steel
UNS NumberG43400
DIN Number1.6511
Material StandardBS 970-3:1991 / ASTM A322
Screw Standard (Metric)DIN 912 / DIN 7991 / ISO 4762
Screw Standard (Inch)ASME B18.3
Thread FormISO Metric / UNC / UNF
Diameter RangeM6-M64 / ¼"-2½"
Tensile Strength930-1080 MPa (135-157 ksi)
Yield Strength785 MPa (114 ksi) min
Hardness28-36 HRC
? All material certified by NABL-accredited laboratory. Ultrasonic and MPI 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.) 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.) Bolts
EN 24 (4340 Equiv.) Nuts
EN 24 (4340 Equiv.) Washers
EN 24 (4340 Equiv.) Studs
EN 24 (4340 Equiv.) Threaded Rods

Technical Data

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

EN 24 (4340 Equiv.) Screws are available in metric M6–M100 and inch ¼″–4″ as standard. Per DIN 912 (hex socket head cap), DIN 7991 (countersunk), ISO 4762. Custom lengths in 5mm increments. Inch dimensions available per ASME B18.3. All EN 24 (4340 Equiv.) screws dimensions conform to applicable DIN, ISO, and ASME B18 standards.

Socket Head Cap Screw Dimensions - Metric (DIN 912 / ISO 4762)

Size (M)Pitch (mm)Head Dia (mm)Head Ht (mm)Hex Socket (mm)Min L (mm)Max L (mm)
M61.0106.0510120
M81.25138.0612160
M101.51610.0816200
M121.751812.01020250
M162.02416.01425300
M202.53020.01730350
M243.03624.01940400
M303.54530.02250500
M364.05436.02760600
M424.56342.03280800
M485.07248.0361001000
M565.58456.0411201200
M646.09664.0461401500

Dimensional & Material Standards

StandardCoversThread
DIN 912Socket head cap screwsMetric
DIN 7991Countersunk socket screwsMetric
ISO 4762Socket head cap screwsMetric
ASME B18.3Socket cap, set, shoulder screwsUNC/UNF
ISO 898-1Mechanical propertiesMetric
Material StandardRequirement
BS 970-3:1991EN 24 bar/rod
ASTM A3224340 bar/rod
EN 10204 3.1Mill test certificate
EN 10204 3.2TPI-witnessed MTC

Material Chemistry

EN 24 (4340 Equiv.) Chemical Composition

EN 24 (4340 Equiv.) Screws 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
? All heats verified by NABL-accredited spectrometry. Full chemical test reports supplied with every batch.

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

Ni (1.3–1.8%) — Toughness & Fatigue Strength
Nickel content in EN 24 provides superior toughness and resistance to impact and fatigue, making these screws ideal for dynamic and high-load applications.
Cr (0.9–1.4%) — Hardenability & Wear Resistance
Chromium enhances hardenability and surface wear resistance, ensuring EN 24 screws maintain strength and integrity even after repeated tightening and loosening cycles.
Mo (0.2–0.35%) — High-Temperature Strength
Molybdenum improves high-temperature performance and prevents softening, allowing EN 24 screws to retain mechanical properties in elevated temperature service.

Fastener Performance

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

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

Screw SizeDry (Nm)Lubricated (Nm)Clamp Load (kN)
M121108845
M1627021690
M20540432140
M24930744200
M3018501480320
M3632002560460
M4251004080620
M4875006000820
?? Anti-galling: Use molybdenum-based anti-seize for alloy steel. Lubricated values assume K=0.16. Avoid over-torquing to prevent thread damage.

Industry Applications

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

EN 24 (4340 Equiv.) Screws 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 screws are widely used in aircraft landing gear, engine mounts, and structural assemblies where high strength-to-weight ratio and fatigue resistance are critical. Supplied to AMS 6414 and BS S157 specifications for aerospace hardware.
Socket head cap screws for connecting rods, crankshafts, and suspension systems in high-performance vehicles and motorsport applications. EN 24’s toughness ensures reliability under dynamic and impact loads.
Fasteners for gearboxes, hydraulic presses, and heavy-duty machine frames where high tensile and shear strength are required. EN 24 screws maintain integrity under shock and vibration.
Used in downhole tools, drill collars, and pressure control equipment where resistance to fatigue and impact is essential. EN 24 screws are specified for critical bolted joints in harsh field environments.

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

EN 24 (4340 Equiv.) Screws 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 84 DIN 85 DIN 912 DIN 913 DIN 914 DIN 915 DIN 916 DIN 6912 DIN 7984 DIN 7985 DIN 7991 DIN 965 ISO 4762 ISO 10642 ISO 14579 ASME B18.3 ASME B18.6.3 EN ISO 4762 IS 1363 IS 1367 SAE J933 SAE J1199
Certifications
ISO 9001:2015NABL LabPED 2014/68/EUMTC 3.1 / 3.2

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

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

Browse expert answers to common questions about EN 24 (4340 Equiv.) Screws 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.) screws selection and pricing.
EN 24 (4340 Equiv.) socket head screws are available to DIN 912 (metric), ISO 4762, DIN 7991 (countersunk), and ASME B18.3 (inch series). Custom thread forms such as UNC, UNF, and BSF can be supplied on request. All screws are manufactured with full traceability and mechanical test certification.
Use a molybdenum-based anti-seize compound (such as Molykote 1000 or Loctite LB 8012) for EN 24 screws, especially in high-load or high-temperature applications. Apply to threads and under the head to prevent galling and facilitate disassembly. Avoid copper-based anti-seize in corrosive environments.
Yes – EN 24 (4340 Equiv.) screws are specifically engineered for high fatigue, shock, and impact resistance. Their nickel-chromium-molybdenum composition and through-hardening capability make them ideal for dynamic and cyclically loaded joints in aerospace, automotive, and heavy machinery.
No formal MOQ for standard sizes (M8-M36) held in stock – we supply from single pieces for urgent maintenance. Custom sizes or non-standard threads typically require a 10 kg minimum. Quantity discounts are available at 50 pcs, 200 pcs, and 500 pcs.

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
  • Canada
  • 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
  • Thailand
  • Vietnam
  • South Korea
  • Japan
  • Brazil