Steel grades are legion. Fascinating in there making is minuscule amounts of this and that added to the charge changing properties quite radically.
Structural steel...wide flange beams, channel shapes along with angle sections (and others) fall under ASTM A36. Fairly moderate requirements for that standard: 36,000 lb minimum tensile yield strength per square inch.
The yield strength is defined as 2% elongation of given cross section. If a 1” square bar of A36 stretches beyond 10.2” under a 36,000# test pull, then it does not comply with A36.
Steel is utterly marvelous at withstanding tension loading; not so good with the compression side of the equation.