I've used probably 10 flat tappet cams in the last 15 years and lost 3 all in the same motor. That was due to me using too much spring pressure and longer rockers. One other motor failed completely but that was because it was old and ragged out so when it got a new cam stuffed in it just blew the bearings right out. Severe rod knock. Doesn't matter much to me what the cams are made of as long as they work, and they usually do. Total cheap cams lost due to metallurgy... 0.