Size 1 1/8, 300M VAR Premium Aircraft Centerless Ground Normalized and Tempered Alloy

(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.

MIL-S-8844 - AMS 6417 - AMS 2300

Color Marking: Ends painted Brown with Yellow Stripe

Physical Conditions E
Surface Condition 4

Stock Lengths: 12' Approx.

Unit of Measure

Specifications

Estimated Weight per Foot	N/A 3.383 lb
Estimated Weight 12-Ft. Bar	N/A 40.59 lb

Analysis

N/A Carbon .40/.43
Manganese .65/.90
Phosphorus .010 Max.
Sulphur .010 Max.
Si. 1.45/1.80
Cr. .70/.95
Ni. 1.65/2.00
Mo. .35/.45
V. .05/.10

Applications

N/A Intended for ultra high strength structural applications with sections 3" or less in thickness at the time of heat treatment in order to insure through-hardening characteristics.

Mechanical Properties

N/A Response to heat treatment and transverse ductility of this alloy are assured by means of tension tests performed on samples taken from mid-radius and center location of the top and bottom of billets or bars. After heat treatment, the following properties are attained:

Nominal Area Square Inches Up to 100 sq. in.
Tensile Strength - 280,000 psi Min
Yield - 230,000 psi Min
Reduction of Area Average All Tests- 30 min
Reduction of Area Lowest Single Test- 25 min

Nominal Area Square Inches Over 100" to 144 sq. in.
Tensile Strength - 280,000 psi Min
Yield - 230,000 psi Min
Reduction of Area Average All Tests- 25 min
Reduction of Area Lowest Single Test- 20 min

Hardening

N/A End-quench hardenability values are Rockwell "C" 55 mimmum at 8/16" and Rockwell "C" 53 minimum at 20/16"

Heat Treating

N/A Normalize—1700°F
Austenitize—1600°F
Quench—Oil, 140°F maximum
Temper—500°/600°F for 270,000 psi strength level