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Waka

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Someone once said there is no such thing as a stupid question only the person asking it.


I have been looking at the festool bits for my drill and I'm unsure of the difference between Pozidrive and Phillips driver bits.

All explanations considered.
 

CHJ

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Waka":38gxru8t said:
Someone once said there is no such thing as a stupid question only the person asking it.


I have been looking at the festool bits for my drill and I'm unsure of the difference between Pozidrive and Phillips driver bits.

All explanations considered.
Basically two incompatible propriety designs, (angles etc. different) (VHS Betamax syndrome)

Phillips most likely seen on electrical goods.

Pozidrive (GKN) (and the USA equivalent Pro-drive) are the ones most likely to be found on woodscrews/general engineering.

Now awaits the flames if I was not technical enough :)
 

Alf

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This explanation seems pretty comprehensive.
Pozidrive screws are the European answer to the Phillips shortcomings. The differences are subtle. At first glance it appears to be a Phillips, but on closer examination you'll notice a second set of cross-blades at the root of the large cross-blades. These added blades are for identification and match the additional makings on the head of Pozi-drive screws, known as "tick" marks. So the marks are for identification. Identification of what?

Two features of the Pozi-drive screw and driver combination make it unique, and superior to the Phillips. First, the tip or the Pozidrive driver is blunt, which also helps it to seat better into the recess in the screw, unlike the Phillips which comes to a sharper point. This becomes a problem as the tooling that forges the recess in the head of the screws begins to show signs of wear. The recess becomes more and more shallow, which means the driver will bottom-out too soon and will cause the driver to cam-out. The second unique feature is the large blades on the driver have parallel faces, where the Phillips blades are tapered. The straight sides of the driver allow additional torque to be exerted without fear of cam-out. Knowing this, we can see why a Phillips driver will have problems driving a screw with a Pozi-recess, as a Pozi-driver would have little luck driving a Phillips head screw. One more tip. In a pinch it is possible to drive Pozi-drive screws with a Phillips driver, but you will need to grind down the tip slightly, and expect some slipping to occur.
Cheers, Alf
 

Waka

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All

Thanks for the response, I am now understanding. Its true what they say; you do learn something new everyday, well I have today.
 

wizer

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Waka":3slyu6tj said:
All

Thanks for the response, I am now understanding. Its true what they say; you do learn something new everyday, well I have today.
me too, I always wondered why so many different x bits in my combination bit-set
 

edmund

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Just for the sake of completeness there's a good pop up with drawings of the standard types of screws on this supplier's website http://www.toolfastdirect.co.uk/acatalog/Brass_Slotted_Countersunk_Woodscrews.html if you click on the "More info" link a couple of lines from the top. Also tells you how to work out gauge size from measuring the screw head, viz. measure in 1/16ths take off 1 and multiply by 2. Quite handy I thought.[/url]
 

Losos

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Waka & all - I've 'discovered' the Tork (Hope I've spelt that right!) system and IMHO it's miles better than either Philips or Pozidrive. Cam out is virtually eliminated, and much more torque can be applied. It's available from Axminster among others and the only negative I've found is that - so far - I can't find any round head versions. Of course you do need a screwdriver with the 'splines' to fit the head.
 

edmund

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Losos is referring to Torx (I'm pretty sure). I have a small ratchet and couple of bits for sticking my car back together. Quite a good definition here for those interested: http://en.wikipedia.org/wiki/Torx.
I just find it annoying that you need so many screwdrivers et al. to take things apart these days :?
 

Jake

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I find both Torx and square drive really irritating and fiddly to get the bit into, whereas with posi the bit catches just by pressing. I've never experienced cam-out, not even once, is it a frequent problem or just a bit of a myth?
 

Chris Knight

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I only use Torx screws if I have a choice. I find them much easier to use and Jake, yes I do get cam-outs with Pozi drive - never with Torx. Also they hardly require any pressure to keep the bit in the screwhead - the holes being parallel sided.
 

Jake

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Presumably that is with a normal drill/driver? I've never really used one for screw-driving. The first cordless I ever bought was an Elu impact driver off Ebay a few years ago, and only subsequently did I get a drill/driver which I only ever use as a drill, as the Elu doesn't try to wrench your wrist off, is about ten times as quick and incomparably more effective. As I say, I've never ever experienced cam-out, and I must have driven well over 10,000 screws with it, so I guess maybe that is another advantage of the impact driver.
 

Chris Knight

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Jake, I agree an impact driver makes a big difference and can reduce cam-out considerably. I have a Hitachi and it's one of my favourite tools - can screw a four inch screw into oak or a small brass screw in jewllery box hinge quite happily. However, I switched to Torx screws before I got the Hitachi and I still prefer Torx even now I have it.
 
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