AMS Specification 4340V High Tensile Steel Alloy Steel

AMS 6414

4340V High Tensile Steel – Bars, Forgings, Tubing & Forging Stock

Steel, Bars, Forgings, Mechanical Tubing – 0.80Cr – 1.8Ni – 0.25Mo (0.38 – 0.43C) – Vacuum Arc Remelted

AS9100D / ISO 9001

Mill Test Reports

2–4 Week Delivery

877-237-6822

Quick Specification Facts

Spec Number AMS 6414 (AMS6414)

Material 4340V High Tensile Steel

Spec Type AMS (Aerospace Material Specification)

Category 4340V High Tensile Steel

Composition 0.80Cr – 1.8Ni – 0.25Mo (0.38 – 0.43C)

Melt Process Vacuum Consumable Electrode Remelted (VAR/CEVM)

Product Forms Bars, Forgings, Mechanical Tubing, Forging Stock

Certification AS9100D / ISO 9001 with full MTR traceability

Specification Overview

AMS 6414 (also referenced as AMS6414) is an SAE International aerospace material specification covering premium aircraft-quality, low-alloy 4340V high tensile steel in the form of bars, forgings, mechanical tubing, and forging stock. Per SAE International, this specification covers "a premium aircraft-quality, low-alloy steel in the form of bars, forgings, mechanical tubing, and forging stock." The nominal chemistry of 0.80% Chromium, 1.8% Nickel, and 0.25% Molybdenum with a carbon range of 0.38–0.43% delivers an exceptional combination of high tensile strength, toughness, hardenability, and fatigue resistance.

A defining feature of AMS 6414 is its dual melting process: the steel is initially produced in an Electric Furnace and then subjected to Vacuum Arc Remelt (VAR), also known as Consumable Electrode Vacuum Arc Remelting (CEVM). This process results in a cleaner, higher-quality steel that meets the rigorous magnetic particle inspection criteria of AMS-2300. The resulting material exhibits excellent transverse ductility and toughness at elevated strength levels, along with impressive shock, impact, wear, and abrasion resistance in its hardened state. Common applications include jet engines, landing gear, and gear boxes.

Available Product Forms

Bars

Forgings

Mechanical Tubing

Forging Stock

AMS 6414 material is supplied as Bars, Forgings, Mechanical Tubing, and Forging Stock per specification requirements. Custom lengths, sizes, and pre-machined forms are available upon request. Contact our materials specialists for non-standard dimensions or specific forging configurations.

Nominal Chemical Composition

Element	Symbol	Nominal %	Notes
Carbon	C	0.38 – 0.43%	Medium carbon – enables heat treatment to high tensile strength
Chromium	Cr	0.70 – 0.90% (~0.80%)	Improves hardenability and corrosion resistance
Nickel	Ni	1.65 – 2.00% (~1.8%)	Enhances toughness, impact resistance, and low-temperature ductility
Molybdenum	Mo	0.20 – 0.30% (~0.25%)	Enhances hardenability and elevated-temperature strength
Manganese	Mn	0.65 – 0.85%	Deoxidizer; improves hardenability and strength
Silicon	Si	0.15 – 0.35%	Deoxidizer; improves strength
Vanadium	V	0.05% min	Grain refinement; improves strength and toughness (the "V" in 4340V)
Iron	Fe	Balance	Base metal

Chemical composition ranges are nominal. Consult the current issue of AMS 6414 for precise minimum/maximum requirements. Aero-Vac provides full mill test reports (MTRs) with certified chemistry for every order.

Key Properties & Specification Details

Property / Attribute	Details
Specification Number	AMS 6414 (AMS6414)
Issuing Organization	SAE International (Society of Automotive Engineers)
Material Type	Premium Aircraft-Quality Low-Alloy Steel
Steel Grade	4340V (AISI / UNS G43406)
Nominal Composition	0.80Cr – 1.8Ni – 0.25Mo (0.38 – 0.43C)
Melt Process	Electric Furnace + Vacuum Arc Remelt (VAR / CEVM)
Available Forms	Bars, Forgings, Mechanical Tubing, Forging Stock
Cleanliness Standard	Meets AMS-2300 magnetic particle inspection requirements
Hardenability	Excellent – responds well to heat treatment; through-hardens in large sections
Toughness & Ductility	Excellent transverse ductility and toughness at high strength levels
Shock & Wear Resistance	Outstanding shock, impact, wear, and abrasion resistance when hardened
Fatigue Resistance	High – superior for cyclically loaded aerospace and structural applications
Magnetic Properties	Magnetic (ferritic/martensitic)
Certification Available	AS9100D / ISO 9001, Certificate of Conformance, MTR

Typical Applications

Jet Engines: Engine components requiring premium aircraft-quality steel with outstanding strength, toughness, and fatigue resistance under extreme operating conditions and cyclic loading.

Landing Gear: High-strength structural landing gear components requiring excellent impact resistance, shock absorption, and wear resistance in hardened condition—a primary application for AMS 6414 material.

Gear Boxes & Transmission Components: Gears, shafts, and gearbox components benefiting from 4340V's exceptional combination of surface hardness, core toughness, and wear resistance.

Aerospace & Defense Structural Components: Aircraft structural members, forgings, and high-load assemblies requiring premium cleanliness (VAR/CEVM process) and predictable high-strength mechanical performance.

High-Load Industrial Applications: Tooling, dies, heavy-duty shafts, and components requiring the superior mechanical properties achievable through heat treatment of this premium aircraft-quality alloy steel.

Frequently Asked Questions – AMS 6414

What is AMS 6414 and what does it cover?

AMS 6414 (also written AMS6414) is an SAE International aerospace material specification covering premium aircraft-quality, low-alloy 4340V high tensile steel in the form of bars, forgings, mechanical tubing, and forging stock. The material is produced via a dual melting process—Electric Furnace followed by Vacuum Arc Remelt (VAR/CEVM)—resulting in a cleaner steel that meets AMS-2300 magnetic particle inspection standards. The nominal chemistry of 0.80% Chromium, 1.8% Nickel, and 0.25% Molybdenum with 0.38–0.43% Carbon delivers outstanding high tensile strength, toughness, shock resistance, and fatigue performance. Common applications include jet engines, landing gear, and gear boxes.

What is the difference between AMS 6414 and AMS 6415?

Both AMS 6414 and AMS 6415 cover 4340 alloy steel in bar, forging, and tubing forms, but they differ primarily in the melting and cleanliness requirements. AMS 6414 specifies Vacuum Consumable Electrode Remelting (VAR/CEVM), which produces a higher-purity, premium aircraft-quality steel meeting the more stringent AMS-2300 magnetic particle inspection criteria. AMS 6415 covers the standard (non-VAR) version of 4340 steel. For the most demanding aerospace applications—such as landing gear and jet engine components—AMS 6414 is typically specified. Aero-Vac can supply material to either specification and will help you determine which is appropriate for your application.

Does Aero-Vac supply AMS 6414 with full mill test reports and certifications?

Yes. All AMS 6414 material supplied by Aero-Vac is fully traceable to mill test reports (MTRs) confirming chemical composition and mechanical properties per the specification. We are AS9100D/ISO 9001 certified with a 99.6% quality rating. Every order ships with certificates of conformance, material certifications, and chemical/mechanical test reports. Electronic delivery of all documentation is available for fast turnaround. For AMS 6414's VAR/CEVM requirements, our material is sourced from qualified mills with full melt process documentation. If your program requires additional special process certifications including AMS-2300 compliance records, our quality team can coordinate as needed.

What sizes of AMS 6414 material does Aero-Vac stock?

Aero-Vac maintains inventory of AMS 6414 material including bars, forgings, mechanical tubing, and forging stock in a range of sizes and configurations. We carry standard round bar diameters and can provide custom-cut lengths from our in-house processing facility at the Port of Kalama. For forgings and forging stock, our team can source specific configurations from our qualified supplier network. Contact us with your specific size, form, and quantity requirements and we will provide a prompt quote with availability and lead time.

What are the typical lead times for AMS 6414 material?

In-stock AMS 6414 material is typically available for same-day or next-day shipment. For custom-cut or specially processed orders, our standard lead time is 2–4 weeks—significantly faster than the industry average of 8–12 weeks. Forgings and specialty items requiring mill production may require 4–8 weeks depending on quantity and dimensions. We prioritize urgent aerospace and defense requirements and will always provide honest, upfront delivery estimates. Rush processing is available on select items.

Can Aero-Vac provide value-added processing for AMS 6414 material?

Yes. Aero-Vac operates a complete in-house processing facility at our Port of Kalama location. For AMS 6414 high tensile steel, we offer precision saw cutting, surface grinding, turning, milling, and heat treatment services. We also provide comprehensive mechanical and non-destructive testing services in-house. Having all capabilities under one roof allows for faster turnaround, tighter quality control, and reduced overall cost compared to using multiple vendors. Contact us to discuss your specific processing requirements for bars, forgings, tubing, or forging stock.

Need AMS 6414 material or a custom quote?

Our alloy steel specialists can provide fast pricing, availability, and technical guidance for your AMS 6414 4340V high tensile steel requirements.