Shoutout to the guy who said 'tenths are for machinists, thousandths are for assemblers'

I was grabbing coffee at the shop near the old Baxter Gear plant and overheard a gray haired guy say that to a trainee. He was talking about holding a plus or minus five tenths tolerance on a simple spacer. It made me stop and think about how often we chase numbers that don't matter for the part's job. That spacer just needed to not bind, not win a beauty contest. Anyone else run into jobs where the print calls for insane precision on a part that just sits there?

3 comments

3 Comments

the_henry2mo ago

Gotta disagree hard on this one. Those tight tolerances exist for a reason, usually to make sure everything fits together down the line. If you let one part get sloppy, it can mess up the whole assembly.

rowank692mo ago

So @the_henry, you've never eyeballed a part and just sent it?

evan1511mo ago

Oh come on, Henry. You're telling me you've never had a bracket that was a hair too tight and you just took a file to it and called it good? I've been building stuff for years and sometimes those "tight tolerances" are just the engineer covering his butt. If the hole is 0.002" off and the bolts still drop in perfect, nobody is going to notice or care. Half the time those specs are based on perfect shop conditions that don't exist in real life anyway. I'd rather get the job done and move on than sit there remaking a part over a tenth of a millimeter.