... length with UT Article: SCM440, AISI 1045, SCM420, Tool steel round bar Grade:42CrMo, S45C, AISI 1045, 20CrMo, SNCM439 etc. as ... by the government, first-choice updating and upgrading products for national key industries of machine, locomotive, ship making, ... , automobile, coal feeder, aviation, space flight, tool and new steel varieties required by national defense construction, defense production and ...