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AISI 4340 Screws Manufacturer & Exporter in India

Explore AISI 4340 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 AISI 4340 Screws?

AISI 4340 screws are high-strength alloy steel fasteners manufactured from chromium-nickel-molybdenum steel conforming to ASTM A574 and SAE J429 standards. This ultra-high-strength steel is heat treated to achieve exceptional tensile and yield properties, making AISI 4340 screws ideal for critical structural and mechanical applications where fatigue resistance and toughness are paramount.

With a typical tensile strength exceeding 930 MPa and excellent through-hardening capability, AISI 4340 screws are widely specified for aerospace, automotive, and heavy engineering assemblies subjected to high loads, impact, and cyclic stresses. Their superior core strength and ductility outperform standard carbon and alloy steel fasteners in demanding environments.

Quick Specifications

MaterialAISI 4340 Alloy Steel
UNS NumberG43400
DIN Number1.6565
Material StandardASTM A574 / SAE J429
Screw Standard (Metric)DIN 912 / 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. Heat treatment and mechanical test reports available on request.

Complete the Fastener Set

Other AISI 4340 Fastener Products Available from RealBolt

RealBolt also manufactures the complete AISI 4340 fastener range from certified alloy steel bar stock, including AISI 4340 Bolts, AISI 4340 Nuts, AISI 4340 Washers, AISI 4340 Studs, and AISI 4340 Threaded Rods. All AISI 4340 fastener types are produced to ASTM with full EN 10204 MTC 3.1/3.2 documentation.
AISI 4340 Bolts
AISI 4340 Nuts
AISI 4340 Washers
AISI 4340 Studs
AISI 4340 Threaded Rods

Technical Data

AISI 4340 Screws Dimensions, Sizes & Thread Standards

AISI 4340 Screws are available in metric M6–M100 and inch ¼″–4″ as standard. Per DIN 912 (socket head cap screw) / ISO 4762. Custom lengths in 5mm increments. Inch dimensions available per ASME B18.3. All AISI 4340 screws dimensions are verified against applicable DIN, ISO, and ASME B18 standards before

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)
M61.0106.0510100
M81.25138.0612150
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
ISO 4762Socket head screwsMetric
ASME B18.3Socket cap, set, shoulder screwsUNC/UNF
DIN 7991Socket countersunk screwsMetric
ISO 10642Socket countersunk screwsMetric
Material StandardRequirement
ASTM A574Alloy steel screws
SAE J429Mechanical properties
EN 10204 3.1Mill test certificate
EN 10204 3.2TPI-witnessed MTC

Material Chemistry

AISI 4340 Chemical Composition

AISI 4340 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 ASTM A574 / SAE J404

ElementComposition (%)
Carbon (C)0.38-0.43
Manganese (Mn)0.60-0.80
Silicon (Si)0.15-0.30
Nickel (Ni)1.65-2.00
Chromium (Cr)0.70-0.90
Molybdenum (Mo)0.20-0.30
Phosphorus (P)0.035 max
Sulfur (S)0.040 max
Iron (Fe)Balance
? All heats verified by NABL-accredited spectrometry. Full chemical test reports available on request.

Why AISI 4340 Alloy Composition Matters for Screws

Ni (1.65–2.00%) — Core Toughness
Nickel content ensures deep hardenability and high impact resistance, making AISI 4340 screws suitable for dynamic and shock-loaded joints.
Cr & Mo — Strength & Fatigue Life
Chromium and molybdenum provide high tensile strength and excellent fatigue resistance, critical for screws in rotating machinery and structural assemblies.
Low P & S — Clean Steel
Strict control of phosphorus and sulfur ensures superior toughness and minimizes the risk of brittle fracture in high-stress applications.

Fastener Performance

AISI 4340 Screws Mechanical Properties & Torque Reference

The table below lists mechanical properties and torque reference for AISI 4340 Screws per ASTM. AISI 4340 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
M20530424140
M24920736200
M3018501480320
M3632002560460
M4251004080650
M4875006000900
?? Anti-galling: Use molybdenum-based anti-seize for alloy steel. Lubricated values assume K=0.16. Avoid over-tightening to prevent thread galling.

Industry Applications

AISI 4340 Screws Applications — Industries & End Uses

AISI 4340 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. Select an industry below to see specific AISI 4340 screws application details and RealBolt stock availability.
AISI 4340 screws are widely used in aircraft landing gear assemblies, structural joints, and engine mounts where high strength-to-weight ratio and fatigue resistance are critical. Qualified to AMS 6415 and MIL-S-5000 for aerospace hardware.
Socket head cap screws and set screws for high-performance engines, transmission assemblies, and suspension systems. AISI 4340’s toughness and strength make it ideal for connecting rods, crankshafts, and chassis fasteners in racing and heavy-duty vehicles.
Critical fasteners for mining equipment, hydraulic presses, and earthmoving machinery. AISI 4340 screws provide reliable performance in high-load, impact, and vibration-prone environments, reducing the risk of fatigue failure.
Used in high-pressure drilling tools, BOPs, and subsea connectors where superior mechanical strength and impact resistance are required. AISI 4340 screws are specified for API 6A and NACE MR0175 compliant assemblies.

AISI 4340 Screws Standards & International Certifications

AISI 4340 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 AISI 4340 Screws from India's Leading Manufacturer — Get a Competitive Quote Today

Partner with RealBolt — India’s leading manufacturer of certified AISI 4340 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.
022-6743-7972
+91 90226 36025
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Answers for Buyers

AISI 4340 Screws — Frequently Asked Questions

Browse expert answers to common questions about AISI 4340 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 AISI 4340 screws selection and pricing.
AISI 4340 socket head cap screws are available to DIN 912 (metric), ISO 4762, and ASME B18.3 (inch series). Countersunk and button head types are supplied per DIN 7991 and ISO 10642. Custom thread forms (UNC, UNF, BSW) and special lengths are available on request with short lead times.
Use a molybdenum-based anti-seize compound (such as Molykote 1000 or Loctite LB 8012) for AISI 4340 screws. Apply to threads and under the head to prevent galling and facilitate removal. Avoid copper-based anti-seize in corrosive environments to prevent galvanic corrosion.
AISI 4340 screws are suitable for service temperatures up to 450°C. For higher temperatures, consider nickel alloy or stainless steel fasteners. Always verify mechanical properties after heat exposure, as strength may decrease above 450°C.
No formal MOQ for standard sizes (M8-M30) held ex-stock – we supply from single pieces for urgent requirements. Custom sizes or special heat treatments may require a 10 kg minimum. Quantity price breaks 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