Can't tell you where to find it, but I happen to have an old data sheet of WEL-TEN 80 that states the following. WEL-TEN 80 is a high strength steel for welded structures. It is a low carbon (0.18%), quenched and tempered, low alloy steel. Chemical and mech. properties are equivalent to ASTM-A-514 Gr.F., Yield 70 kg/mm2, Tensile 80-95 kg/mm2. Low Hydrogen electrodes are to be used for welding. Pre-heating to about 250 deg.F is recommended. Brinell Hardness 320 to 360. Hope this helps.