Not exactly. Things are done in decimal fractions until you get down to around 1/64", but any farther and they're done in thou (1/1000" aka mils) or tenths (1/1

Not exactly. Things are done in decimal fractions until you get down to around 1/64", but any farther and they're done in thou (1/1000" aka mils) or tenths (1/10000"). There's overlap, machinists will use thou up to and sometimes beyond a full inch.