Hi!

Some where on this forum there is a link to a copy of H&H catalog 1912. On the page 39 there is a add of a 450 Nr.2 pearcing a 9/16" steel plate. And ofcoarse this is only an add but the old steel was crap, tryed to weld some old beams from a ship yard once and it was almost made of pure coal and acted closely to cast iron. So its probably possible if one are careful in choosing the right steel.