Reading ETKA hardware #s

Jim Haseltine Jim at
Mon Oct 8 23:49:30 EDT 2001

----- Original Message -----
From: "Huw Powell" <audi at>
> > >
> >
> > > N 011 445 7   Hex bolt (M10x45x20)
> > > 10mm dia, 45mm long, 2.0 pitch?
> I think the "20" refers to an unthreaded portion of the bolt.  to the
> best of my peering the fiche/etka never seemed to specify thread pitch.

Etka does specify thread pitch sometimes.

N 010 142 7  Hex bolt M12x1,5x50 = 50mm M12 bolt 1.5mm pitch.

The problem with metric 'M' sizing is that there is more than one 'fine'

Std 'M'
M6 (6mm) - pitch 1.00mm
M8 (8mm) - pitch 1.25mm
M10 (10mm) - pitch 1.50mm
M12 (12mm) - pitch 1.75mm

Fine 'M'
M8 - pitch 1.00mm
M10 - pitch 1.00mm
M10 - pitch 1.25mm
M12 - pitch 1.25mm
M12 - pitch 1.5mm

So both M10 and M12 are available in 1 std and 2 fine threads - imagine if
you can, the fun I had after I had dropped a tray of 500 M8, 10 & 12 nuts.
Segregation by size was no problem, but several hours of sorting threads by
test screwing nuts on to known pitch bolts was a real PITA.

Additional point -
Technically, a 'bolt' has unthreaded shank, if the threads are continuous
it's a 'set screw'.


Jim Haseltine

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