I'm relatively new at balcksmithing.
A local blacksmith explained that when the steel heats to the point that it's no longer attracted to a magnet then about the right temperature to quench.

He said this is easier and more accurate than judging temperature by color because it works the same under any light conditions.

The quenchant would be water.

A couple of questions,
Will it work at all,
Will this work well with 1040 steel, in small sections up to about 1.5 inches square.

He also recomended plunging the end of the tool being hardened about two inches into the quenchant and then moving it up and down a little until it cools completerly. Later he would dress the tool and finally temper it by heating it from the end that you strike and watch the heat colors flow down toward the working end.

Any opinions

The answer is.... it depends.

It depends on the tool or knife that you are making. If it is a quick-and-dirty tool such as a quick punch or chisel, then heating to non-magnetic, quenching the shaped end leaving the other end hot, then a quick sanding and letting the colors run before quenching the whole tool is the fastest method. The heat treating of a tool or knife becomes more complicated the more the critical the properties of the final tool and Rockwell hardness becomes.

Heat Treat

I found that the ceramic doughnut magnets you get at radio shack on a copper wire work easiest. You wave the metal under/along side the magnet and look for movement like a pendulum. I was just trying to calibrate my eye some, not yet to heat treat yet.

http://www.iforgeiron.com/forum/f11/non-magnetic-heat-magnets-14222/

Phil

dickb,
Here is what I believe an appropriate URL that may lend some light on your inquiry.
I found this thread under

Not to get too far off-topic, but dickb, water isn't an appropriate quenchant for all steels. In fact it's pretty darned risky for some. When you say "the quenchant would be water," is that because you've done some research or testing that indicates it's an appropriate quenchant for your steel?

If you're going to use a magnet, you generally don't want to quench from just non-magnetic. A hundred or so degrees hotter than non-magnetic is more like it for most medium or high carbon, simple steels.

Hello everyone. I am just getting started blacksmithing and really enjoy your site.

I am new also, but have used this magnet method for hardening drilling extension rod, which I've been told is high carbon. I've made strikers from it. It seems to work just fine for that purpose.