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

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

EN 24 (4340 Equivalent) nuts are high-strength alloy steel fasteners manufactured from EN 24 (AISI 4340) bar stock, a nickel-chromium-molybdenum alloy renowned for its exceptional toughness and fatigue resistance. These nuts are typically supplied in the quenched and tempered condition, achieving high tensile and yield strengths suitable for critical bolted joints in demanding engineering applications.

EN 24 nuts are widely specified for use in heavy-duty mechanical assemblies, high-stress flange connections, and rotating equipment where both strength and ductility are essential. They conform to international standards such as ASTM A194 Grade 7 and DIN 934, ensuring compatibility with high-strength bolts and studs in the oil & gas, power generation, and heavy machinery sectors.

Quick Specifications

MaterialEN 24 (AISI 4340)
UNS NumberG43400
DIN Number1.6511
Material StandardBS 970-3:1991 / ASTM A322
Nut Standard (Metric)DIN 934 / ISO 4032
Nut Standard (Inch)ASME B18.2.2
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 EN 24 nuts supplied with full traceability and laboratory certification. Hardness and mechanical test reports available.

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.) 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.) Bolts
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.) Nuts Dimensions, Sizes & Thread Standards

EN 24 (4340 Equiv.) Nuts are available in metric M6–M100 and inch ¼″–4″ as standard. Per DIN 934 (hex nut) / ISO 4032. Custom thread pitches and heavy hex patterns available. Inch sizes per ASME B18.2.2. All EN 24 (4340 Equiv.) nuts dimensions are verified against applicable DIN, ISO, and

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

Size (M)Pitch (mm)A/F (mm)Height (mm)
M81.25136.5
M101.5178.0
M121.751910.0
M162.02413.0
M202.53016.0
M243.03619.0
M303.54624.0
M364.05529.0
M424.56534.0
M485.07538.0
M565.58545.0
M646.09551.0
M726.010558.0
M806.011564.0
M1006.014580.0

Dimensional & Material Standards

StandardCoversThread
DIN 934Hex nutsMetric
ISO 4032Hex nutsMetric
ASME B18.2.2Hex & heavy hex nutsUNC/UNF
BS 1768Hex nuts (inch)BSW/BSF
Material StandardRequirement
BS 970-3:1991EN 24 bar/rod
ASTM A3224340 bar/rod
ASTM A194 Gr.7Mechanical properties
EN 10204 3.1Mill test certificate
EN 10204 3.2TPI-witnessed MTC

Material Chemistry

EN 24 (4340) Chemical Composition

EN 24 (4340 Equiv.) Nuts 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 spectro-tested and certified. Full chemical analysis provided with every batch.

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

Ni-Cr-Mo Alloying — Strength & Toughness
The combination of nickel, chromium, and molybdenum in EN 24 (4340) provides outstanding tensile strength, impact resistance, and ductility, making these nuts ideal for high-load and fatigue-prone bolted joints.
Controlled Carbon — Hardenability
A carbon content of 0.36–0.44% ensures deep hardenability during heat treatment, allowing EN 24 nuts to achieve uniform strength and hardness throughout their cross-section.
Low S & P — Clean Steel
Strict limits on sulphur and phosphorus reduce the risk of embrittlement and improve the reliability of nuts in critical service conditions.

Fastener Performance

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

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

Nut SizeRecommended Torque (Nm)Proof Load (kN)
M129562
M16230120
M20450190
M24780275
M301600430
M362800620
M424200830
M4862001100
?? Lubrication: Use molybdenum disulphide or graphite-based anti-seize for optimal preload and to prevent galling. Torque values are for lubricated assembly (K=0.16).

Industry Applications

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

EN 24 (4340 Equiv.) Nuts 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) nuts are widely used for high-pressure vessel closures, heat exchanger channel covers, and ASME B16.5/B16.47 flange connections in refineries and petrochemical plants, where high strength and impact resistance are critical.
Hex nuts and heavy hex nuts for bolted joints in mining crushers, draglines, and earthmoving equipment, where shock loading and fatigue are common. EN 24 nuts provide the toughness required for reliable service.
Used in steam turbine casings, HRSG ducting, and boiler manway covers, EN 24 nuts withstand high mechanical loads and thermal cycling in power plants.
EN 24 (4340) nuts are specified for landing gear assemblies, engine mounts, and structural joints in aircraft and military vehicles, where high strength-to-weight ratio and fracture toughness are essential.

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

EN 24 (4340 Equiv.) 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, hardness test certificate, dimensional inspection report, and proof load test records — available on request for all orders.
Standards
DIN 934 DIN 980 DIN 982 DIN 985 DIN 439 DIN 557 DIN 562 ISO 4032 ISO 7040 ASME B18.2.2 EN ISO 4032 BS EN ISO 4032 IS 1363 IS 1364 IS 6623 IS 3757 SAE J995 SAE J1199 UNI 5588 CSN 021123 PN 82144
Certifications
ISO 9001:2015PED 2014/68/EUNABL LabMTC 3.1 / 3.2

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

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

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

Browse expert answers to common questions about EN 24 (4340 Equiv.) Nuts 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.) nuts selection and pricing.
EN 24 (4340) nuts are available to DIN 934 (metric hex), ISO 4032, ASME B18.2.2 (inch hex and heavy hex), and BS 1768 (inch hex). Custom thread forms such as UNC, UNF, BSW, and BSF can be supplied on request. All nuts are manufactured from certified EN 24/4340 bar and supplied with full traceability.
For EN 24 (4340) nuts, use a molybdenum disulphide or graphite-based anti-seize compound to prevent galling and ensure consistent preload. Avoid copper-based anti-seize in corrosive or high-temperature environments. Always apply lubricant to both threads and nut bearing surfaces for optimal performance.
Yes – EN 24 (4340) nuts, when properly heat treated, retain good impact toughness down to -50°C, making them suitable for low-temperature and cryogenic applications such as LNG plants and cold storage vessels. Impact test certification can be provided on request.
There is no formal MOQ for standard sizes (M12-M36) available ex-stock – single piece orders are accepted for urgent requirements. Custom sizes or special coatings may require a minimum batch of 10 kg. Quantity discounts are available at 50, 200, and 500 pieces.

Industrial Cities We Serve:

  • Ahmedabad
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  • Bengaluru
  • Chennai
  • Coimbatore
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  • Hazira
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Countries We Export To:

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