Odp: [sdiy] Metric OT rant

[Roman]

Hi Harry and all,

----- Original Message ----- 
From: harry <harrybissell at prodigy.net>

> HA ! now if I could only learn the difference between an M5 and an M8
> screw.   :^P
> 
> Seriously... we get to think in a system.  For me, the 4-40, 6-32, 8-32, and
> 10-32
> are easy to regognize on sight and  I could tell you right off what size tap
> drill, etc.
> For metric, even after I multiply by .03937... I still don't know shit.

well, it's obvius M8 is the fat one, while M5 the more skinier...
But what a heck is this 4-40 or 8-32 crap? 4 is the diameter
and 40 - length? Or this 17/32 thing. I can't divide numbers
just like that! It takes a while (I'm that stupid) to see 5/16
is smaller than 11/32.

BTW, I use 40 instead of 0.03937. I mean, just multiply mm by 40
and you get more or less the 'mills'. Acurate enough at PCB design
to see more or less how big the component etc. is.
 
> but for tooling, metric is an evil European plot (perhaps a French plot ?
> ;^)
> to hobble America by forcing us to buy two sets of all our tooling...

it's not that different. E.g. 1/4'' chafts and 6mm shafts. A knob for
1/4 will fit on 6mm knob. If you're purist, wrap the shaft in foil
to fill the small gap.
Recently (and finally) I got those electric-goldmine's Bourns pots.
They have like 3/8 (?) shaft. For me it's 9.5mm. Too bad there's
no such thing here as 9.5-8.5-7.5 etc. stepper drill, but I can live
just in this case with normal 9.5mm drill.
But anyway it's 0.5mm difference from standard 10mm, about the
error margin of pot placement anyway.

AND, I have succesfully screw metric screws into imperial bushings
several times.


> And to harass us by having us tell our childern "Son... bring me the 9/16
> open end
> wrench... or is that an M14 ???... well bring both.... and make sure they
> get back
> into the right toolboxes...."

That's why I only have adjustable wrench :)

Roman