Posted by Gordon on Friday, July 14, 2006 at 5:07PM :
In Reply to: For you metalurgists out there posted by Doc Dave on Friday, July 14, 2006 at 2:02PM :
...cheaper in the long run.
If you heat it red hot and let it cool slowly it'll be softer than you started with (probably) so it will tend to bend more before shearing.
It you get it red hot and then quench it in oil or water it'll be harder, but more brittle, which is probably what you want with a shear pin I think.
If you knew exactly what the chemistry of the original bolt was, you could probably heat it to a specific temperature and then quench it, then re-heat it to another (lower) specific temperature -- and you'd have pretty much the same item as your shear pin. What we in the trade call 'Quench and temper'
Or you could just go and buy the right bit before something expensive breaks 'cause your pin is either too hard or too soft.
Gordon