RBW wrote:
I have a old steel t-square (18 X 30) that has become corroded and
dirty to the extent the numbers are hard to read. I have tried a few
solvents and steel wool but not much luck. Does anyone have any
suggestions for cleaning this flat steel tool. Thanks
Robert

Vinegar saturated with salt - soak (fully covered!) overnight. Rust and
stains will be gone.
Rinse well and immediately oil.

Ken.