"Ignoramus32726" wrote in
message
It used to be that 0 degrees F could be a problem for impact
strength. Ax heads needed to be warmed above freezing to avoid
shattering.

This was due to sulphur content, right? And then people figured out
that sulphur needed to be removed, right?

i

AFAIK until at least the 1920's it was assumed that sulphur caused
more problems with hot steel than cold, so if it didn't suffer from
"hot shortness" at the mill it would be good enough in service.

Fred Colvin, 1922:
"Sulphur is of most trouble to rolling and forging operations
when conducted at a red heat. It makes steel tender and brittle
at that temperature - a condition known to the workmen as
" red-short.'' It seems to have little or no effect upon the
physical properties of cold steel - at least as revealed by the
ordinary testing machines - consequently many specifications do
not set any limit on sulphur, resting on the idea that if sulphm-
[sic] is
low enough not to cause trouble to the manufacturer during rolling,
it will not cause the user any trouble. "
http://www.archive.org/stream/cu3192...49615_djvu.txt

US engineers didn't seriously encounter and have to solve problems
with tool steel in Arctic cold until WW2. Maybe the Soviets kept their
Siberian experience a military secret??

jsw