0.8 um Symbol on print ?

Hi,

I have to quote this job but i can't find any information on this symbol

" 0.8 um "

Can anyone help me out what this means ? Looks like it has something to do with the surface finish.

Thanks
Ray

It is a specification of surface finish. 0.8um is metric (micrometers). It is equivilant to 32uin (microinches.) This finish is obtainable with turning or milling.

Yup. He's correct!

What does he win?

Scott

Thanks Guys..............That's what i thought but i wasn't sure.

Have you seen a series of triangles used for surface finish symbols? Its an older German method and some still use it today. My previous employer is probably still using this method.

If you run into a row of triangles, break out a copy of the Machinery Handbook. They're in there. It's amazing what's in that book!

Scott