A good size gas or oil furnace for annealing and case-hardening.
The process of case-hardening has been well conducted when the surface of the metal proves sufficiently hard to resist a file.
It was that case-hardening experience which had worked the callous metamorphosis.
As a boy, I used to be expert in this case-hardening of files and steel, and my knowledge now stood me in excellent need.
All she required was the case-hardening of the world, which would leave an iron surface upon which the dog trains could travel.
Case-hardening is one of the most common defects in improperly dried lumber.
It is distinct from the well-known "case-hardening" effect spoken of above, which is caused by unequal moisture conditions.
Case-hardening is the name given to a simple process, by which the outside of iron may be turned into steel.
In the case-hardening department, next door, there are six huge ovens with sliding fronts.