cherrybomb
Well-known member
Whats the differences,and which bits interchange in posi drive,jis and phillips?Will using the wrong bit,set you up for failure?
The Difference In Bits
- Thread starter cherrybomb
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Wamsutta
Well-known member
Phillips left. Pozidriv on the right:
Wamsutta
Well-known member
Dave455
Well-known member
Phillips and JIS are very similar. As I understand it, JIS was only sufficiently different from Phillips to avoid paying royalties to Phillips Screw, or their successors. They have now changed the pattern so newer Japenese screws are interchangable with Phillips. You only really need JIS to work on older Japanese cars and bikes. A JIS driver will fit a Phillips screw (though not as well as the proper driver) but not vice versa.
Pozidriv are totally different. They are NOT interchangable with anything (apart from Supadriv which is really only a variation). Phillips screws were designed for the first generation of mechanical drivers, and they simply 'cam out' of the screw when it's done up, which works, but isn't ideal.
Pozidriv are designed not to do that, and were designed for torque controlled screwdrivers. It's a much better design, and should have replaced Phillips instantly, but didn't. Size for size, a Phillips driver will fit inside a Pozidriv recess but there's a load of slop and it won't grip well. A Pozidriv driver will not fit a Phillips recess, unless you drop a size, which doesn't really work either!
Strangely, Pozidriv was an instant success in the U.K. which hadn't really adopted Phillips anyway, and you will hardly ever find Phillips screws here, other than in the aviation industry which has used them for years. Ditto most of Europe.
I notice the difference. Probably 95 % of the cross head screws I drive are Pozidriv. My PB Swiss drivers are generally a superb fit and I get loads of torque. If I encounter a Phillips (generally only on Japanese cars) and it's a bit rusted in, I find the things really frustrating as I have to push the driver so hard!
Pozidriv are totally different. They are NOT interchangable with anything (apart from Supadriv which is really only a variation). Phillips screws were designed for the first generation of mechanical drivers, and they simply 'cam out' of the screw when it's done up, which works, but isn't ideal.
Pozidriv are designed not to do that, and were designed for torque controlled screwdrivers. It's a much better design, and should have replaced Phillips instantly, but didn't. Size for size, a Phillips driver will fit inside a Pozidriv recess but there's a load of slop and it won't grip well. A Pozidriv driver will not fit a Phillips recess, unless you drop a size, which doesn't really work either!
Strangely, Pozidriv was an instant success in the U.K. which hadn't really adopted Phillips anyway, and you will hardly ever find Phillips screws here, other than in the aviation industry which has used them for years. Ditto most of Europe.
I notice the difference. Probably 95 % of the cross head screws I drive are Pozidriv. My PB Swiss drivers are generally a superb fit and I get loads of torque. If I encounter a Phillips (generally only on Japanese cars) and it's a bit rusted in, I find the things really frustrating as I have to push the driver so hard!
Last edited:
AZ Pete
Well-known member
Very informative
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rlitman
Well-known member
Phillips left. Pozidriv on the right:
These are both "ACR" (anti camout ribbed) variations.
Pozi driv can be identified by the X embossed on the screw head, and that extra set of tiny ribs on the driver. They don't actually engage anything, and are only there to make it easier to tell the difference.
Lots of people use Phillips drivers on pozi driv screws. Anyone who's had the frustration assembling Ikea furniture probably knows what it is like.
Musicinabottle
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As a carp, I had no idea. Torx is king these days so I never gave it much thought.
Krokodil
Well-known member
JIS are very common on commercial office copier/printer machines.
They are also sometimes identifiable by a smot dot on the top of the screw head. A quick Google image search for “JIS screw head” will show this clearly.
They are also sometimes identifiable by a smot dot on the top of the screw head. A quick Google image search for “JIS screw head” will show this clearly.