Patent ID: 7744708

Claim:
A method for producing a tubular steel bar, comprising: providing a steel bar of desired size, comprising: about 0.13 to 0.35% carbon; about 0.8 to 2.0% manganese; about 0.10% to 0.70% silicon; about 0.01% to 0.07% aluminum; up to about 0.50% chromium; up to about 0.25% molybdenum; and up to about 0.30% vanadium; heating the bar to an elevated temperature; quenching the bar, wherein the bar is not subject to heat treatment subsequent to quenching; wherein the bar as-quenched has an ultimate tensile strength of about 1400 MPa or greater, a yield strength to ultimate tensile strength ratio of between about 0.65 and 0.90, and an elongation of about 12% or greater; and forming the as-quenched bar into a desired shape at a temperature less than about 80° C.; wherein the as-formed bar has a fatigue life of greater than about 300,000 cycles as measured under laboratory testing when the region about at least one formed regions is subjected to cyclic stresses above about 450 MPa.