Anet A8 Inductive sensor with glass

I'm sharing this with you, because it's working perfectly in my printer.
I started to use a capacitive sensor because my glass is 0.4mm and the inductor didn't work, and the capacitive get many erros because doesn't work ok with temperature.
So I remenber that I read somewhere that inducor sensor work ok with iron and baddly with alloy.
I bought a sheet of iron 22cm x 22cm x 0.8mm and put between the alloy heated bed and the glass, and perfect now the inductive sensor works like a sharm no mo