[CaptBubba]

Quote:

Originally posted by wallijonn how do you measure lumber in the metric system? somehow i can't see a carpenter being able to not ask for a 2 by 2. (have you noticed that a 2 by 2 isn't really a 2 by 2?, 3x3 isn't really 3" by 3". etc.?)

That's because they are sawn at 2"x2", but the boards that you recieve have been planed and rounded to eliminate the large rough saw marks, hence they are smaller than the original measurement. Sometimes this process fails and that's when you get some rough areas on a board. If they didn't trim at all, the whole board would look like that. You can get raw 2"x2" and it is actually 2"x2", but it looks like crap and tends to be very uneven.

And a hogshead is a measure of liquid capacity as well, basically a large barrel.

geom_tol, that's when you switch to um, or nm. 10um is easy enough to say.

edit: dang letter mu won't show up right...

 

[CaptBubba]

delete this post

 

[geom_tol]

Quote:

Originally posted by CaptBubba geom_tol, that's when you switch to um, or nm. 10um is easy enough to say.

um and nm are not used on engineering drawings except when specifying surface finish.
The um is just too small a unit to be very useful, it is also confusing to use both mm and um when describing things.

 

[wallijonn]

http://web.ita.doc.gov/ticwebsite/FA...256b3e00682edf!OpenDocument

i believe Japanese metric bolts have a different pitch than British metric bolts.

some interesting reading: http://6mm.com/z/1916metricmag.htm

http://www.tysknews.com/Depts/Metric...ergonomics.htm

http://www.cnn.com/2002/SHOWBIZ/book...alder.measure/ (Why the Meter is a Crock)

http://www.microlink.co.uk/units.html (some history)