Originally Posted by race8082  need to achieve an 8 finish in a.437 bore hole is .700 deep material is 15-5 rc43. with .0003 total tolerance on dia. Thanks for any help. |
how many?
i don't know much about surface finish numbers, but a quick google reveals disparity, some reference a mirror finish, others brush etc.
is it .437 or is it .4375? makes difference if you're holding .0003....in that the first thing to try (if the later) is a sharp 7/16 reamer, run it slowly, feed it slowly and retract and slowly all with flood and you can get a good finish.
If that finish isn't good enough, its not difficult, but can be time consuming, to put a mirror finish on via lapping. ream with an undersized reamer and start lapping with progressively finer compound. mirror will start coming out at 600 and really show its stuff at 1000.