+912267437972

+919022636025

enquiry@real-bolt.com

Contact Us

AISI 4340 Washers Manufacturer & Exporter in India

Explore AISI 4340 Washers Manufacturer & Exporter in India manufactured for demanding industrial applications with reliable strength, corrosion resistance and compliance with international standards.
Request a Quote
View Products

-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 Washers?

AISI 4340 washers are high-strength alloy steel flat or shaped washers manufactured from AISI 4340 (UNS G43400) bar or plate, conforming to ASTM A829 and ASTM A194 standards. This alloy is renowned for its exceptional toughness, fatigue resistance, and high tensile strength, achieved through heat treatment and tempering. AISI 4340 washers are widely specified for critical bolted joints in heavy-duty engineering, where both mechanical strength and resistance to impact or cyclic loading are paramount.

With a typical tensile strength exceeding 930 MPa and excellent through-hardening properties, AISI 4340 washers are the preferred choice for aerospace, power generation, oil & gas, and heavy machinery applications. They are available in a range of hardness levels (28-44 HRC) to suit both structural and high-temperature bolting assemblies.

Quick Specifications

MaterialAISI 4340 Alloy Steel
UNS NumberG43400
DIN Number1.6565
Material StandardASTM A829 / ASTM A194
Washer Standard (Metric)DIN 125 / DIN 127 / DIN 6916
Washer Standard (Inch)ASME B18.22.1
Hardness Range28-44 HRC
Diameter RangeM6-M100 / ¼"-4"
Tensile Strength930-1080 MPa
Yield Strength785-930 MPa
Impact Toughness= 35 J (Charpy V-notch)
? All washers supplied with full traceability and laboratory-certified mechanical properties. Hardness and PMI 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 Screws, 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 Screws
AISI 4340 Studs
AISI 4340 Threaded Rods

Technical Data

AISI 4340 Washers Dimensions, Sizes & Thread Standards

AISI 4340 Washers are available in metric M6–M100 and inch ¼″–4″ as standard. Per DIN 125 (flat), DIN 127 (spring), DIN 6916 (structural), and ASME B18.22.1. Custom OD/ID and thickness available. Metric and inch sizes supplied to order. All AISI 4340 washers dimensions conform to applicable DIN, ISO, and ASME B18 standards.

Flat & Spring Washer Dimensions - Metric (DIN 125 / DIN 127)

Size (M)Inner Dia (mm)Outer Dia (mm)Thickness (mm)
M66.4121.6
M88.4161.6
M1010.5202.0
M1213.0242.5
M1617.0303.0
M2021.0373.0
M2425.0444.0
M3031.0564.0
M3637.0665.0
M4243.0786.0
M4849.0926.0
M5657.01058.0
M6465.01158.0
M7273.013010.0
M8081.014010.0
M100101.018012.0

Dimensional & Material Standards

StandardCoversType
DIN 125Flat washersMetric
DIN 127Spring lock washersMetric
DIN 6916High-strength structural washersMetric
ASME B18.22.1Plain & lock washersInch
ISO 7089Flat washersMetric
ISO 7090Chamfered washersMetric
Material StandardRequirement
ASTM A8294340 alloy steel plate/bar
ASTM A194Washer mechanicals
EN 10204 3.1Mill test certificate
EN 10204 3.2TPI-witnessed MTC

Material Chemistry

AISI 4340 Chemical Composition

AISI 4340 Washers 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 A829

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 spectro-tested and certified by NABL-accredited laboratory. Full PMI available on request.

Why AISI 4340 Alloy Composition Matters for Washers

Ni (1.65–2.00%) — Toughness & Fatigue Resistance
Nickel content in AISI 4340 provides superior impact toughness and fatigue resistance, making these washers ideal for dynamic and cyclic loading environments.
Cr & Mo — Hardenability & Strength
Chromium and molybdenum ensure deep hardenability and high tensile strength, allowing washers to maintain their properties even in thick sections and at elevated temperatures.
Low P & S — Clean Steel for Reliability
Strict control of phosphorus and sulfur ensures high purity, reducing the risk of embrittlement and guaranteeing consistent performance in critical bolted joints.

Fastener Performance

AISI 4340 Washers Mechanical Properties & Torque Reference

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

Bolt SizeRecommended Washer Hardness (HRC)Max Clamp Load (kN)
M1228-3270
M1630-36120
M2032-38180
M2434-40260
M3036-44400
M3636-44600
?? Washer hardness should always be less than bolt hardness to prevent galling. For high-strength bolts, use through-hardened AISI 4340 washers.

Industry Applications

AISI 4340 Washers Applications — Industries & End Uses

AISI 4340 Washers 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 washers application details and RealBolt stock availability.
AISI 4340 washers are specified for API 6A and ASME B16.5/B16.47 flange assemblies in high-pressure wellhead, manifold, and pipeline connections. Their high strength and toughness prevent embedment and maintain preload under cyclic loading and vibration.
Used in bolted joints of mining crushers, excavators, and earthmoving equipment, AISI 4340 washers provide reliable load distribution and resist deformation under extreme impact and shock loads.
Flat and spring washers for steam turbine casings, HRSG ducting, and boiler drum connections, where high clamp loads and thermal cycling demand superior fatigue and creep resistance.
AISI 4340 washers are used in landing gear assemblies, engine mounts, and structural joints in aircraft and military vehicles, where high strength-to-weight ratio and impact resistance are critical.

AISI 4340 Washers Standards & International Certifications

AISI 4340 Washers 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 125A DIN 126 DIN 127 DIN 128 DIN 433 DIN 434 DIN 436 DIN 440 DIN 6796 DIN 6797 DIN 9021 ISO 7089 ISO 7090 ISO 7091 ISO 7092 ISO 7093 ISO 7094 ASME B18.21.1 EN ISO 7089 BS 4320 IS 5372 IS 1367
Certifications
ISO 9001:2015EN 10204 3.1/3.2NABL LabPED 2014/68/EU

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

Partner with RealBolt — India’s leading manufacturer of certified AISI 4340 Washers — 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
Email Us

Answers for Buyers

AISI 4340 Washers — Frequently Asked Questions

Browse expert answers to common questions about AISI 4340 Washers 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 washers selection and pricing.
AISI 4340 washers are available to DIN 125 (flat), DIN 127 (spring), DIN 6916 (structural), ISO 7089/7090, and ASME B18.22.1 (inch). Custom OD, ID, and thickness can be supplied to drawing. All washers are manufactured from ASTM A829/AISI 4340 plate or bar and supplied with EN 10204 3.1/3.2 certification.
Yes – AISI 4340 washers are specifically designed for use with high-strength bolts (ASTM A193 B7, A490, 10.9, 12.9, etc.). Their high hardness and toughness prevent embedding and maintain preload, even under heavy dynamic or impact loads. Always match washer hardness to bolt grade for optimal performance.
AISI 4340 washers maintain mechanical properties up to 450°C continuous service. For higher temperatures or creep resistance, consider alloy upgrades such as AISI 4140 or Inconel 718. Consult our engineering team for temperature-specific recommendations.
No MOQ for standard sizes (M12-M36) in stock – we supply from single pieces for urgent requirements. Custom sizes or special hardness have a 10 kg minimum. Price breaks 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