I have a new little problem with the engine I'm rebuilding (Skoda 120L '70s, RWD, RME): after milling, adjusting and cleaning the crankshaft, camshaft and pulley I found out that their woodruff keys have a lot of play. I torqued the pulley 1/2 way and still feel a play when rotating it, so...I need to make new keys. I'm not scared about adjustment work, but the question is: which kind of steel should suffice?
I have no access to "named" or "numbered" steels, but just scraps I can get, which includes: suspension spring leaves, stainless steel bars, construction (structural) mild steel, broken/old drill bits, old engine valves, old wrenches. So please don't refer me to "use C-1035 or C-45" because I won't be able to find it that way...although I know what they are.
Any idea how hard or soft the keys should be? The sprockets are steel, driven by chain.