[TheForge] Quenching mild steel

[Shannell Sugrue]

With all the talk lately of heat treating, Ive wondered for a while about
the details of quenching mild or 1018 steel? ie the problems with drilling
after a quench, is this toughness? and changing the yield point of mild
steel for tong handles etc.
 What temps is it safe to quench below and notice no significant difference
to the steel? I usually go by sound once its black, if it sizzles too much
when it hits the water I put it down for 5 more minutes. I know you cant
really harden mild steel, although super quech seems to work well enough,
but what properties are changable by quenching and at what temps I guess is
my Q?