This chromium-molybdenum alloy is one of the most widely used aircraft steels because of its combination of weldability, ease of fabrication, and mild hardenability. In relatively thin sections it will respond to heat treatment to high strength levels and yet in the normalized condition it has adequate strength for many applications. When resistance to wear and abrasion is required, it may be nitrided.
This grade is a quality product melted under the best steelmaking practices for aircraft quality steels. It is vacuum degassed to meet the magnetic particle inspection standards of AMS 2301.

This chromium nickel molybdenum alloy is a widely used deep-hardening constructional steel. It is used at a variety of strength levels and at each level possesses remarkable ductility and toughness. With its high alloy content uniform hardness is developed by heat treatment in relatively heavy sections. High fatigue strength makes E-4340 ideal for highly stressed parts. It maintains its strength and hardness at elevated temperatures.

This grade is available as electric furnace vacuum degassed steel to meet the high aircraft quality standards of AMS 2301. Thus, it is suitable for the fabrication of parts which may be subjected to magnetic particle inspection.

This grade is also available as a Premium Aircraft Quality product. The regular aircraft quality material is remelted in a vacuum using consumable electrode practice. This results in a much cleaner steel meeting the magnetic particle test requirements of AMS-2300 and insures a steel of the highest quality with excellent transverse ductility and toughness at high strength levels.

This chromium nickel molybdenum alloy is a widely used deep-hardening constructional steel. It is used at a variety of strength levels and at each level possesses remarkable ductility and toughness. With its high alloy content uniform hardness is developed by heat treatment in relatively heavy sections. High fatigue strength makes E-4340 ideal for highly stressed parts. It maintains its strength and hardness at elevated temperatures.

This grade is available as electric furnace vacuum degassed steel to meet the high aircraft quality standards of AMS 2301. Thus, it is suitable for the fabrication of parts which may be subjected to magnetic particle inspection.

This grade is also available as a Premium Aircraft Quality product. The regular aircraft quality material is remelted in a vacuum using consumable electrode practice. This results in a much cleaner steel meeting the magnetic particle test requirements of AMS-2300 and insures a steel of the highest quality with excellent transverse ductility and toughness at high strength levels.

This chromium nickel molybdenum alloy is primarily a carburizing grade capable of attaining high case hardness with high core strength and toughness. Its high alloy content makes it suitable for components with relatively heavy sections. The combination of high alloy content and low carbon makes it possible to achieve a high core hardness with a narrow hardness range between heavier and thinner sections.

It is an alloy that offers strength with excellent toughness and ductility, and it may be used to advantage without carburizing. Carburized, a highly wear resistant case is produced which is useful in extremely difficult applications.

The AIRCRAFT QUALITY grade is produced following the best electric furnace steel making practices. It is vacuum degassed to insure meeting the magnetic particle standards of AMS 2301.

This grade is also available as a Premium Aircraft Quality product using the consumable electrode vacuum remelting process. This results in a much cleaner steel meeting the magnetic particle test requirements of AMS 2300 and insures a steel of the highest quality with excellent transverse ductility and toughness at high strength levels.

This chromium nickel molybdenum alloy is primarily a carburizing grade capable of attaining high case hardness with high core strength and toughness. Its high alloy content makes it suitable for components with relatively heavy sections. The combination of high alloy content and low carbon makes it possible to achieve a high core hardness with a narrow hardness range between heavier and thinner sections.

It is an alloy that offers strength with excellent toughness and ductility, and it may be used to advantage without carburizing. Carburized, a highly wear resistant case is produced which is useful in extremely difficult applications.

The AIRCRAFT QUALITY grade is produced following the best electric furnace steel making practices. It is vacuum degassed to insure meeting the magnetic particle standards of AMS 2301.

This grade is also available as a Premium Aircraft Quality product using the consumable electrode vacuum remelting process. This results in a much cleaner steel meeting the magnetic particle test requirements of AMS 2300 and insures a steel of the highest quality with excellent transverse ductility and toughness at high strength levels.

This grade is a chromium nickel molybdenum alloy modified by the addition of vanadium. It is a high strength alloy with good ductility and impact strength. The lowering of the carbon content from the more common .40 per cent level improves its toughness and ductility, and it also limits the strength level to which the alloy- can be used.

It is available as a consumable electrode vacuum remelted product. This method of melting improves the transverse ductility of the grade at its high usable strength. It also improves the non-metallic cleanliness, making it the most appropriate for the fabrication of parts subjected to magnetic particle inspection.

(E4340 Modified)
This steel is a chromium nickel molybdenum alloy similar to 4340, but modified by the addition of vanadium and a higher silicon content. The silicon acts to displace the 500°F temper embrittlement range to higher temperatures. The overall alloy content acts to produce higher strength levels without the necessity of increasing the carbon content. Thus, this alloy offers a combination of toughness and ductility at high strength levels. It is a deep hardening steel with excellent torque properties. It has high fatigue and creep characteristics and maintains its strength at moderately high temperatures.

The grade is available as a consumable electrode vacuum remelted product. This insures a steel of the highest quality with excellent transverse ductility and toughness at high strength levels. It also insures the non-metallic cleanliness of this alloy meeting AMS 2300, thus making it most suitable for the fabrication of parts subjected to magnetic particle inspection.

HS 220-18 is a low carbon, high silicon, chromium nickel molybdenum alloy steel. It was one of the first grades developed in the high strength class, combining strength with toughness and ductility. It has relatively high impact resistance because of its low notch sensitivity at the high hardness at which this alloy is commonly used. It is available as a basic electric furnace air melt and vacuum degassed product to meet the high aircraft quality standards of AMS 2301. In addition, this alloy is produced as Special Aircraft Quality to insure transverse ductility and toughness.