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AISI 4340 Studs Manufacturer & Exporter in India

Explore AISI 4340 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 AISI 4340 Studs?

AISI 4340 studs are high-strength alloy steel fasteners manufactured from chromium-nickel-molybdenum steel conforming to ASTM A193 Grade B7M or equivalent. This alloy is renowned for its exceptional toughness, fatigue resistance, and high tensile strength, making it ideal for critical bolted connections in demanding environments. AISI 4340 studs are typically supplied quenched and tempered, achieving superior mechanical properties and consistent performance under cyclic loading and elevated temperatures.

These studs are widely specified for pressure vessel closures, high-pressure piping, and structural applications in oil & gas, power generation, and heavy engineering sectors. Full traceability and mechanical certification are provided for every batch, ensuring compliance with international standards and project specifications.

Quick Specifications

MaterialAISI 4340 Alloy Steel
UNS NumberG43400
DIN Number1.6582
Material StandardASTM A193 / ASTM A320
Stud Standard (Metric)DIN 976 / DIN 975 / ISO 898-1
Stud Standard (Inch)ASME B16.5 / ASME B18.31.2
Thread FormISO Metric / UNC / UNF
Diameter RangeM8-M100 / ?"-4"
Tensile Strength930-1080 MPa (135-157 ksi)
Yield Strength785 MPa (114 ksi) min
Hardness24-36 HRC
? All material certified by NABL-accredited laboratory. Heat treatment and mechanical test reports supplied.

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 Screws, AISI 4340 Washers, 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 Screws
AISI 4340 Washers
AISI 4340 Threaded Rods

Technical Data

AISI 4340 Studs Dimensions, Sizes & Thread Standards

AISI 4340 Studs are available in metric M6–M100 and inch ¼″–4″ as standard. Per DIN 976 (full thread) / DIN 975 (threaded rod) / ASME B16.5 (flange studs). Custom lengths available in 5mm increments. Inch dimensions per ASME B18.31.2. All AISI 4340 studs dimensions conform to applicable DIN, ISO, and ASME B18 standards.

Stud Dimensions - Metric (DIN 976)

Size (M)Pitch (mm)Thread Length (mm)Min L (mm)Max L (mm)
M81.2524401000
M101.530501200
M121.7536601500
M162.048802000
M202.5601002000
M243.0721202500
M303.5901503000
M364.01081803000
M424.51262103500
M485.01442404000
M565.51682804000
M646.01923205000
M726.02163605000
M806.02404006000
M1006.03005006000

Dimensional & Material Standards

StandardCoversThread
DIN 976Stud bolts, full threadMetric
DIN 975Threaded rodsMetric
ASME B16.5Stud bolts for flangesUNC
ASME B18.31.2Continuous thread studsUNC/UNF
ISO 898-1Mechanical propertiesMetric
Material StandardRequirement
ASTM A193 B7MQuenched & tempered alloy steel
ASTM A320 L7Low temp service
EN 10204 3.1Mill test certificate
EN 10204 3.2TPI-witnessed MTC

Material Chemistry

AISI 4340 Chemical Composition

AISI 4340 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 ASTM A29 / AISI 4340

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. PMI available on request.

Why AISI 4340 Alloy Composition Matters for Studs

Ni (1.65–2.00%) — Toughness & Fatigue Resistance
Nickel content in AISI 4340 provides outstanding toughness and fatigue resistance, making these studs ideal for cyclically loaded and impact-prone connections.
Cr & Mo — Strength & Hardenability
Chromium and molybdenum ensure high tensile strength and deep hardenability, allowing large-diameter studs to achieve uniform properties throughout their cross-section.
Low Impurity Levels
Strict phosphorus and sulfur limits guarantee reliable performance in critical bolted joints, reducing the risk of embrittlement and failure under stress.

Fastener Performance

AISI 4340 Studs Mechanical Properties & Torque Reference

The table below lists mechanical properties and torque reference for AISI 4340 Studs per ASTM. AISI 4340 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 anti-seize (Molykote 1000). Lubricated values assume K=0.16. Avoid copper-based anti-seize for high-strength alloy steel.

Industry Applications

AISI 4340 Studs Applications — Industries & End Uses

AISI 4340 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. Select an industry below to see specific AISI 4340 studs application details and RealBolt stock availability.
AISI 4340 studs are the preferred choice for ASME Section VIII pressure vessel closures, API 6A wellhead flanges, and high-pressure manifold connections. Their high strength and toughness ensure reliable sealing in critical oilfield and refinery applications.
Used for steam turbine casing studs, HRSG ducting, and boiler manway closures, AISI 4340 studs withstand high temperatures and cyclic stresses, maintaining preload integrity in thermal cycling environments.
AISI 4340 studs are specified for large machinery assembly, crane joints, and bridge structural connections where high fatigue resistance and impact toughness are essential for safety and longevity.
Studs for dragline, shovel, and excavator assemblies are manufactured from AISI 4340 to resist shock loading, vibration, and abrasive wear in harsh mining environments.

AISI 4340 Studs Standards & International Certifications

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

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

AISI 4340 Studs — Frequently Asked Questions

Browse expert answers to common questions about AISI 4340 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 AISI 4340 studs selection and pricing.
AISI 4340 studs are supplied to DIN 976 (full thread), DIN 975 (threaded rod), ASME B16.5 (flange studs), and ASME B18.31.2 (continuous thread). Mechanical properties conform to ASTM A193 Grade B7M or A320 L7. Custom thread forms (UNC, UNF, metric fine) and special coatings are available on request.
Use molybdenum-based anti-seize compound (such as Molykote 1000 or Loctite LB 8012) for AISI 4340 studs. Apply to threads and nut faces to prevent galling and ensure accurate preload. Avoid copper-based anti-seize, which can promote galvanic corrosion in high-strength alloy steel applications.
Yes – AISI 4340 studs, when heat treated to ASTM A193 B7M or A320 L7, are suitable for continuous service up to 450°C. For higher temperatures, consult our engineering team for alternative grades or special heat treatments.
No MOQ for standard sizes (M12-M36) available ex-stock – single pieces can be supplied for urgent maintenance. Custom sizes or special coatings may require a 10 kg minimum. Bulk 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
  • 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