Mil-s-16974 mil spec all material responses
Mil-s-16974,grade 8630,cond f mil spec all material responses
Mil-s-16974 mil spec single material response or astm a304, gr 4140h assn std single material response
Mil-s-16974 mil spec 1st material response or astm a304 assn std 2nd material response
Aisi 4130 assn std single material response or mil-s-16974,gr 4130 cond n mil spec single material response