Annealing Of Rifle Components At Springfield Armory
: CASE-HARDENING OR SURFACE-CARBURIZING
: The Working Of Steel
In general, all forgings of the components of the arms manufactured
at the Armory and all forgings for other ordnance establishments
are packed in charcoal, lime or suitable material and annealed
before being transferred from the forge shop.
Except in special cases, all annealing will be done in annealing
pots of appropriate size. One fire end of a thermo-couple is inserted
in the center of the annealing
ot nearest the middle of the furnace
and another in the furnace outside of but near the annealing pots.
The temperatures used in annealing carbon steel components of the
various classes used at the Armory vary from 800 deg.C. To 880 deg.C. or
1,475 to 1,615 deg.F.
The fuel is shut off from the annealing furnace gradually as the
temperature of the pot approaches the prescribed annealing temperature
so as to prevent heating beyond that temperature.
The forgings of the rifle barrel and the pistol barrel are exceptions
to the above general rule. These forgings will be packed in lime
and allowed to cool slowly from the residual heat after forging.