Some articles on hardening grades, hardening grade, hardening:
... The first air hardening grade tool steel was mushet steel, which was known as air-hardening steel at the time ... Modern air-hardening steels are characterized by low distortion during heat treatment because of their high-chromium content ... They also harden in air because they have less alloyants than oil-hardening grades ...
Famous quotes containing the words grades and/or hardening:
“Kindliness seems to exist primarily as an animal instinct, so deeply rooted that mental degeneracy, which works from the top down, does not destroy it until the mind sinks to the lower grades of idiocy.”
—Charles Horton Cooley (18641929)
“With sixty staring me in the face, I have developed inflammation of the sentence structure and definite hardening of the paragraphs.”
—James Thurber (18941961)