Identifying case hardened steel?

[solemnwarning]

I'm not sure if this is the right place to ask, but does anyone know how to identify case hardened steel? There's a slightly worn fork in a gearbox I'm rebuilding which I think will be fine to reuse as long as it isn't case hardened, since the wear would expose the soft steel earlier if it is.

Thanks

 

[cumbriasteve]

I usually find a hacksaw blade will slide over case hardened instead of leaving a score mark.. a bit of an amatuer way to test it but works for me.

 

[brightspark]

as said above or put a fine file across an unworn part then the worn bit. the file will slide over if hardened without marking the metal . if its soft it will start to cut and has worn through

 

[solemnwarning]

I can score the metal with a cheap file, looks like it isn't hardened

Thanks