owly in furnace to a good cherry red. The heat depends on the
quality and the analysis of steel and the recommended actions of
the steel maker should be carefully followed. When withdrawn from
the fire the die should be quenched as shown in Fig. 80 with the
face of die down and the back a short distance out of the water.
When the back is black, immerse all over.

[Illustration: FIG. 80.--Quenching a die, face down.]

If such a tank is not at hand, it would pay to rig one up at once,
although a barrel of brine may be used, or the back of the die
may be first immersed to a depth of about 1/2 in. When the piece
is immersed, hold die on an angle as in Fig. 81.

[Illustration: FIG. 81.--Hold die at angle to quench.]

This is for the purpose of expelling all steam bubbles as they
form in contact with hot steel. We are aware of the fact that a
great many toolmakers in jewelry shops still cling to the overhead
bath, as in Fig. 82, but more broken pieces and more dies with
soft spots are due to this method than to all the others combined,
as the water strikes one spot in force, contracting the surface
so much faster than the rest of the die that the results are the
same as if an uneven heating had been given the steel.

TAKE TIME FOR HARDENING.--Uneven heating and poor quenching has
caused loss of many very valuable dies, and it certainly seems
that when a firm spends from $75 to $450 in cutting a die that
a few hours could be spared for proper hardening. But the usual
feeling is that a tool must be hurried as soon as the hardener
gets it, and if a burst die is the result from either uneven or
overheated steel and quenching same without judgment, the steel
gets the blame.

[Illustration: FIG. 82.--An obsolete method.]

Give the steel a chance to heat properly, mix a little common sense
with "your 30 years experience on the other fellows steel." Remember
that high-carbon steel hardens at a lower heat than low-carbon
steel, and quench when at the right heat in the two above ways,
and 99 per cent of the trouble will vanish.

When a die flies to pieces in quenching, don't rush to the
superintendent with a "poor-steel" story, but find out first why it
broke so that the salesman who sold it will not be able to harden
piece after piece from the same bar satisfactorily. If you find
a "cold short," commonly called "a pipe," you can lay the blame
on the steelmaker. If it is a case of overheating and quenching
when too hot, you