peed steels containing vanadium have
a mean efficiency of 108.9, as against a mean efficiency of 61.9
obtained from those without vanadium content." A wide range of
vanadium content in steel, from 0.5 to 1.5 per cent, is permissible.

An ideal analysis for high-speed steel containing 18 per cent tungsten
is a chromium content of approximately 3.85 per cent; vanadium, 0.85
to 1.10 per cent, and carbon, between 0.62 and 0.77 per cent.

DETRIMENTAL ELEMENTS.--Sulphur and phosphorus are two elements known
to be detrimental to all steels. Sulphur causes "red-shortness"
and phosphorus causes "cold-shortness." The detrimental effects
of these two elements counteract each other to some extent but
the content should be not over 0.02 sulphur and 0.025 phosphorus.
The serious detrimental effect of small quantities of sulphur and
phosphorus is due to their not being uniformly distributed, owing
to their tendency to segregate.

The manganese and silicon contents are relatively unimportant in
the percentages usually found in high-speed steel.

The detrimental effects of tin, copper and arsenic are not generally
realized by the trade. Small quantities of these impurities are
exceedingly harmful. These elements are very seldom determined
in customers' chemical laboratories and it is somewhat difficult
for public chemists to analyze for them.

In justice to the manufacturer, attention should be called to the
variations in chemical analyses among the best of laboratories.
Generally speaking, a steel works' laboratory will obtain results
more nearly true and accurate than is possible with a customer's
laboratory, or by a public chemist. This can reasonably be expected,
for the steel works' chemist is a specialist, analyzing the same
material for the same elements day in and day out.

The importance of the chemical laboratory to a tool-steel plant
cannot be over-estimated. Every heat of steel is analyzed for each
element, and check analyses obtained; also, every substance used
in the mix is analyzed for all impurities. The importance of using
pure base materials is known to all manufacturers despite chemical
evidence that certain detrimental elements are removed in the process
of manufacture.

The manufacture of high-speed steel represents the highest art
in the making of steel by tool-steel practice. Some may say, on
account of our increased knowledge of chemistry and metallurgy,
that the making of such steel has ceased to be an