A high-strength steel structural member comprising a welded hot-rolled high-strength steel elongated structural member (20, 30, 40, 50, 60, 70, 80) having a uniform cross-sectional configuration over its length, the cross-sectional configuration including a web portion (21, 31, 41, 51, 61, 71, 94) and first and second flange portions (23, 24, 33, 34, 43, 44, 53, 54, 63, 64, 73, 74, 83, 84, 92, 93, 95, 96) extending from said web portion (21, 31, 41, 51, 61, 71, 94), said web portion having an average thickness less than the average thickness of said first and second flange portions (23, 24, 33, 34, 43, 44, 53, 54, 63, 64, 73, 74, 83, 84, 92, 93, 95, 96), said structural member (20, 30, 40, 50, 60, 70, 80), formed of high-strength steel having a tensile strength of at least about 120,000 psi (827.36 MPa) and a yield strength of at least about 90,000 psi (620.52 MPa), characterized in that said structural member (20, 30, 40, 50, 60, 70, 80) is formed by welding a first structural unit (25, 35, 45, 55, 65, 75) to a second structural unit (26, 36, 46, 56, 66, 76), the first structural unit having a first web precursor portion and a first flange precursor portion, the second structural unit (26, 36, 46, 56, 66, 76) having a second web precursor portion and a second flange precursor portion, each unit (25, 26, 35, 36, 45, 46, 55, 56, 65, 66, 75, 76) having an L-shaped cross-section along the complete unit length, the weld joining said web precursor portions of said first and second structural units (25, 26, 35, 36, 45, 46, 55, 56, 65, 66, 75, 76) together whereby the web precursor portions together form the member web portion (21, 31, 41, 51, 61, 71, 94) and the first and second flange precursor portions respectively form the member first and second flange portions (23, 24, 33, 34, 43, 44, 53, 54, 63, 64, 73, 74, 83, 84, 92, 93, 95, 96), and the weld extending along the length of the uniform cross-sectional configuration of said structural member (20, 30, 40, 50, 60, 70, 80) between said first and second flange portions (23, 24, 33, 34, 43, 44, 53, 54, 63, 64, 73, 74, 83, 84, 92, 93, 95, 96) at a neutral axis of said member (20, 30, 40, 50, 60, 70, 80), said first and second flange portions (23, 24, 33, 34, 43, 44, 53, 54, 63, 64, 73, 74, 83, 84, 92, 93, 95, 96) each extending at about a 90° angle from opposite ends of said member web portion (21, 31, 41, 51, 61, 71, 94), each said first and second flange portion (23, 24, 33, 34, 43, 44, 53, 54, 63, 64, 73, 74, 83, 84, 92, 93, 95, 96) intersecting the web portion (21, 31, 41, 51, 61, 71, 94) to form a round corner having inner and outer radii, and said first and second flange portions (23, 24, 33, 34, 43, 44, 53, 54, 63, 64, 73, 74, 83, 84, 92, 93, 95, 96) providing with the member web portion (21, 31, 41, 51, 61, 71, 94) load bearing capacity to said structural member (20, 30, 40, 50, 60, 70, 80), and in that the composition of the high-strength steel comprises, by weight percent, carbon, about 0.30 to about 0.65% manganese, about 0.30 to about 2.5% at least one of the group consisting of aluminum, niobium, titanium, and vanadium, and mixtures thereof, about 0.03 to about 0.35%, and iron and production impurities, the balance. carbon, about 0.30 to about 0.65% manganese, about 0.30 to about 2.5% at least one of the group consisting of aluminum, niobium, titanium, and vanadium, and mixtures thereof, about 0.03 to about 0.35%, and iron and production impurities, the balance.