On Wed, 14 Oct 2009 14:05:05 +0100, Dave Osborne wrote:

PeterC wrote:
On Fri, 09 Oct 2009 01:08:08 +0100, Frank Erskine wrote:

On Thu, 08 Oct 2009 22:55:21 +0100, "Dave Plowman (News)"
had this to say:

It's all such a botch though, isn't it? ALL for the sake of so-called
standardisation. Where does real engineering fit into all of this?

Yup - it was standardised, now it ain't.

Even Thatcher daredn't attack 19" racks - 10s of millions (at least) of
complex units (1.75" IIRC) that would need rewiring if changes needed.

19" Racks have been metricated for donkey's years.

Width of faceplate = 19" = 482.6mm rounded to 483mm

Gap between rack strips (width of opening) = 455mm (typical)

Width of box = 450mm (typical)

Height of faceplate (1U) = 1.75" = 44.45mm rounded to 44.5mm

Height of box = 43mm (i.e. typically slightly less than height of faceplate)

Overall size of conventional floor-standing cabinet typically 600, 800,
900mm wide and typically 600, 700, 800, 900mm deep, etc.

Looks as if the metric measurements have been kludged to fit.

Thanks for the info.
--
Peter.
The head of a pin will hold more angels if
it's been flattened with an angel-grinder.