I thought I would offer a little information on Posi Drive screwdrivers and
bits. After the questions appeared on the list about posi drive, I went
down the hall and asked one of our engineers here at the Mechanics Tools
Division about them. To be honest, I was never really sure what the
difference was myself and therefore qualify as DPO (I would'a used a
Phillips and never known better). He said that a posi drive (which my
company manufactures also) is merely a phillips type bit with a series of
serrated transverse ridges on each of the four flanks that is designed to
"bite" into the metal of a fastener (screw). He showed me some that we
market under the MAC Tools brand side by side with regular Phillips. I
asked him if there was any difference in the fastener pattern (screw head)
itself between posi drive and regular Phillips and he said there was not.
Its just a standard phillips pattern screw. He said its up to the user's
discretion whether or not to use a posi drive or standard Phillips on a
particular application. A posi drive is used in applications where its
likely that the screw will be difficult to remove and may strip as a result.
He said the only drawback is that the posi drive slightly cuts into the
metal of the screw head as it bites into it. That's how it grips. But this
seems like a very minor concern compared to a potentially stripped screw
head. This is just one engineer's explanation who knows nothing about
Triumphs (albeit a guy who designs drive tools for a living). By the way,
MAC wants way too much money for them. If you can find them at Kmart, I'd
just buy them there. Hope this sufficiently muddies up the water on the
subject of posi drive. Regards, Greg (the not-so-knowledgeable tool man)
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