So you've never encountered 1/2" UNC, 1/2" UNF and 1/2" UNEF and variants in the same size?
You should get out more
I know they specify tolerances. I mean tolerance classes: https://en.wikipedia.org/wiki/Unified_T ... ce_classesGlennW wrote: ↑Thu Oct 04, 2018 11:47 amThey don't??John Hasler wrote: ↑Thu Oct 04, 2018 11:25 am Don't forget tolerance classes, which are usually ignored by maintenance people replacing hardware. ISO doesn't seem to have them (which is not necessarily good)
External Tolerances:
Pitch Dia.: 4,5,6,7,8,9
Major Dia.: 4,6,8
Position: e,f,g,h
Internal Tolerances:
Pitch Dia.: 4,5,6,7,8
Minor Dia.: 4,5,6,7,8
Position: G,H
LOL. Fair enough, but again, "common man". Other than missile systems machinists ordering or making to exacting specifications, or guys restoring/repairing aircraft systems, most of use don't have concern for that in day to day (home or otherwise) shop projects. And as Glenn pointed out, metric has the same range of specifications, so the multiplier effect applies to both. But given the larger magnitude of metric fasteners to already required, after applying all that equivalently (modulo classes maybe?), it just makes metric fasteners all the more onerous in my view.John Hasler wrote: ↑Thu Oct 04, 2018 11:25 am Don't forget tolerance classes, which are usually ignored by maintenance people replacing hardware. ISO doesn't seem to have them (which is not necessarily good).
Not in any practical way, and maybe, if I lived in the UK. I've encountered them with about the same frequency as "lock in" pitches, which is to say very VERY rarely. And not something anyone I know (US) would even consider stocking in-shop, or expect the local fastener store to carry (though they may?) I don't think I've ever encountered an EF in "real life" (automotive, home, etc). I seem to encounter the metric pitch variety pain almost every time I have to deal with it (ok, probably 10-20% realistically). That's not even apples and oranges. More like apples and plantains.Magicniner wrote: ↑Thu Oct 04, 2018 12:08 pm So you've never encountered 1/2" UNC, 1/2" UNF and 1/2" UNEF and variants in the same size?
You should get out more
So, you are referring to the fact that ISO doesn't use the actual word "Class" but instead uses a number and a letter to represent the same.John Hasler wrote: ↑Thu Oct 04, 2018 12:16 pm I know they specify tolerances. I mean tolerance classes: https://en.wikipedia.org/wiki/Unified_T ... ce_classes
I can't find anything equivalent to the UN "classes" but I would not be surprised if it existed. Do you have a link?GlennW wrote: ↑Thu Oct 04, 2018 12:33 pmSo, you are referring to the fact that ISO doesn't use the actual word "Class" but instead uses a number and a letter to represent the same.John Hasler wrote: ↑Thu Oct 04, 2018 12:16 pm I know they specify tolerances. I mean tolerance classes: https://en.wikipedia.org/wiki/Unified_T ... ce_classes
SAE (Society of Automotive Engineers)