These are oil-hardening steels of relatively high hardenability. Their chromium content provides good hardness penetration, and the molybdenum imparts uniformity of hardness and high strength. These grades are especially suitable for forging because they have self-scaling characteristics. They respond readily to heat treatment and are comparatively easy to machine in the heat treated condition. They resist creep in temperatures up to 1000°F and maintain their properties even after long exposure at these relatively high working temperatures. With a combination of such highly desirable properties as good strength and wear resistance, excellent toughness coupled with good ductility, and the ability to resist stress at elevated temperatures, it is understandable why these are widely used and highly successful alloy steels.

This material is also available as leaded steel. The addition of lead improves machinability without sacrificing other desirable properties, with the exception that the use of this material is not recommended for applications over 400°F, since at elevated temperature ductility is low.

The following specifications are generally applicable for 4140/42 Heat Treated Rounds: ASTM A 193, Grade B7; ASTM A 434, Grades BC and BD.

Oil Quenched and Tempered — Machine Straightened

Stock Lengths 20' Approx.
Unit of Measure

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Item #

Estimated Weight per Foot

Estimated Weight 20-Ft. Bar

N/A .1671 lb N/A 3.341 lb
N/A .2610 lb N/A 5.220 lb
N/A .3739 lb N/A 7.517 lb
N/A .5116 lb N/A 10.23 lb
N/A .6682 lb N/A 13.36 lb
N/A .8457 lb N/A 16.91 lb
N/A 1.044 lb N/A 20.88 lb
N/A 1.263 lb N/A 25.27 lb
N/A 1.504 lb N/A 30.07 lb
N/A 2.046 lb N/A 40.93 lb
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