[TheForge] Trenton ID

[Andy Vida]

Steve Smith wrote:
> 
> Is there an advantage to preheating to 500? I have no idea, just hadn't
> heard of doing this before.

	As I mentioned in another post, we'd (NJBA) always gone to
	300-350.  This year, for whatever reason, they were taking
	them to about 500.  Didn't seem to have drawn the temper.
	I reground about half of the dozen or so anvils and the
	original steel faces were still quite resistant to the
	abrasives.  I was, to be honest, a bit surprised.

	As to your question, if you mean why preheat at all, it is
	my belief that a slow cool from a tempering heat (let's
	just call it 350*F) reduces the chances of developing stresses
	that will end up in latent cracking, which in turn leads to
	failure under impact, which makes for sharp little bullets
	flying around the shop and a loused up anvil.  Manufacturers 
	say it isn't needed, but I don't trust that so much.  Anvils 
	often have sharp edges that must endure high impacts.  I see 
	fit to give those high stress structures every chance to be 
	as tough and long lasting as possible.  Look at it this way: 
	if you have only one anvil, why not best ensure that it will 
	last your entire lifetime?  A few extra hours to heat and let
	slowly cool cannot hurt you.  This year was either the fourth
	or fifth anvil rebuilding event and as far as I know not a
	single one of the beasts has failed yet.