... Steel Checked by mating part Machined by NC Machine 1.Cage and Flapper Valve2.Investment Casting 3.Stainless Steel, Alloy Steel4 ... Phosphated and Black Oxide7.Hardnes:HRC56-HRC615F-6R flapper valve Cage Mdl.G CageFlapper Valve CageInvestment Casting Stainless Steel, Alloy SteelChecked ... ,BS, JIS, UNI, ANSI, ISO etc. 5F-6R flapper valve Cage Mdl.G ...