Carbon In Tool Steel
: HARDENING CARBON STEEL FOR TOOLS
: The Working Of Steel
Carbon tool steel, or tool steel as it is commonly called, usually
contains from 80 to 125 points (or from 0.80 to 1.25 per cent)
of carbon, and none of the alloys which go to make up the high
speed steels. This was formerly known also as crucible or cast
steel, or crucible cast steel, from the way in which it was made.
This was before the days of steel castings. The advent of these
caused so much confusion that the term was soon dropped. When we
say tool steel, we nearly always refer to carbon-tool steel,
high-speed steel being usually designated by that name.
For many purposes carbon-steel cutters are still found best, although
where a large amount of material is to be removed at a rapid rate,
it has given way to high-speed steels.