"Pozidriv" [was Re: Tools (was: IBM 5155 analogue display fault]

[Pete Turnbull]

On May 31 2005, 21:15, der Mouse wrote:
> > I have a minimal tookit (flat blade, Phillips, Pozidriv, Torx,
Allen
> > keys) upstairs, [...]
>
> Which reminds me - I've seen this "Pozidriv" screw drive mentioned
> elsewhere in this thread, as if it were a common type.  Since there
is
> no screw drive type I know by that name, this leads me to wonder,
what
> is it?  (It may be another name for one I know, or it may be one I
> don't know but which is common in circles I've never moved in, or
> perhaps I misread the references and it's not actually that common.)

The URL Randy posted has a good picture.  Pozidriv/Supadriv are similar
to Philips, but the angles on the point of the driver are slightly
different and the facets are ground flat in both directions, unlike
Philips which are conical, which means that the driver grips the screw
slightly better and both are less prone to wear.  The intent is that
when high turning force is applied, the driver won't ride out of the
screw head, which happens with Philips screws.  Another design feature
is that the driver, if it's the correct size, is guaranteed to grip the
screw, so you can pick up a screw with the driver and know it won't
fall off while you're trying to insert it into a hole in an awkward
place.  Assuming the driver isn't excessively worn from being misused
on Philips screws, of course :-)

In practice, Pozidriv sizes are also slightly different from Philips so
the screwdrivers are not interchangeable.  They are widely used in
Europe, almost to the exclusion of Philips screw heads.

-- 
Pete						Peter Turnbull
						Network Manager
						University of York