Size 1 1/4, 4330 MOD VAR Premium Aircraft Centerless Ground Normalized and Tempered Alloy

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.

MIL-S-8699 - AMS 6411 - AMS 6427 - AMS 2300

Color Marking: Ends painted Gold with Pink Stripe

Physical Conditions E
Surface Condition 4

Stock Lengths: 12' Approx.

Unit of Measure

Specifications

Estimated Weight per Foot	N/A 4.176 lb
Estimated Weight 12-Ft. Bar	N/A 50.12 lb

Analysis

N/A Carbon .23/.33
Manganese .80/1.00
Phosphorus .015
Sulphur .015
Si. .20/.35
Cr. .75/.95
Ni. 1.65/2.00
Mo. .35/.50
V. .05/.10

Applications

N/A Intended for high strength structural applications with good ductility and relatively high impact strength. In order to insure through- hardening characteristics when oil quenched, it may be used in section thicknesses up to 2 1/2" diameter round at time of heat treatment.

Mechanical Properties

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

Cross Section Area Square Inches Up to 144", incl.
Tensile Strength - 220,000 psi Min
Yield - 185,000 psi Min
Reduction of Area Average All Tests- 35 % min
Reduction of Area Lowest Single Test- 30 % min

Cross Section Area Square Inches Over 144" to 225"
Tensile Strength - 220,000 psi Min
Yield - 185,000 psi Min
Reduction of Area Average All Tests- 30 % min
Reduction of Area Lowest Single Test- 25 %min

Cross Section Area Square Inches Over 225"
Tensile Strength - 220,000 psi Min
Yield - 185,000 psi Min
Reduction of Area Average All Tests- 25 % min
Reduction of Area Lowest Single Test- 20 % min

Longitudinal properties
Tensile Strength - 220,000 psi Min
Yield - 185,000 psi Min
Elongation in 2" - 10 min.
Reduction of Area % - 35 min
V-Charpy Ft. Lbs. - 15 min.

Hardening

N/A End-quench hardenability values are Rockwell "C" 49 minimum at 14/16" and Rockwell "C" 45 minimum at 24/16"

Heat Treating

N/A Normalize—1700°F;
Austenitize—1600°F;
Quench—Oil, 150°F maximum
Temper—575°F minimum for 220,000 min. psi strength level
850°F minimum for 180,000 min. psi strength level