[T3] Common Hardware Sizes and BelMetric

[Jim Adney]

On 22 Oct 2014 at 11:48, Dave Hall wrote:

> Adriel, I don't mean to mislead you.  It's probably what they call coarse
> that's usually needed.  I call it standard, which depends on the bolt
> diameter but I've not been looking in a catalogue.  Fine is used
> occasionally, the 'other' is the normal one.  

If you look at a catalog of taps, or a copy of the Machinery's 
Handbook, you'll find that most metric threads come in 3 or 4 
different pitches. Most have only 2 in general use, and in many 
cases, you're only likely to come across 1 of those.

The same is true in inch sizes. For example 1/4-20 and 1/4-28 are 
both common, but 1/4-32 and 1/4-40 also exist. You won't find the 
latter 2 in any hardware store, but they are used in special 
applications, often not incorporating something we might call a bolt.

-- 
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Jim Adney, jadney at vwtype3.org
Madison, Wisconsin, USA
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