New valve springs with larger diameters require new retainers to handle the springs' higher pressure. COMP Cams' standard steel retainers are made of 4140 chromemoly with a black oxide finish. Their tool steel is approximately 33% lighter than standard steel and 2-4 grams heavier than titanium. When upgrading from steel to titanium retainers, you gain speed and power because titanium is lighter and stronger. COMP Cams' titanium design prevents retainer splitting that can tear up an engine at 10,000 RPM.