I believe ASTM steel standards were adopted nearly a hundred years ago. 4140 is 4140. Advancements in the knowledge of metallurgy are inarguable. Advances in quality that match the the advances in knowledge...not so much. Ask welders...ask machinists that work in the industry. Modern, generally imported steel, even at my end user level is terrible. Cavities, slag inclusions, hard inclusions are common and are readily apparent in welding and cutting. Maybe something to do with the millions of tons of scrap we exported . A couple of fellows with borescopes have noted serious defects in stainless steel barrels sent in for rebores right here on the 'fire recently. Which, sorry, has nothing to do with boat tails.
