Identifying PZ and PH screw

[john2k]

I have the following two screws pictured below and the instructions say to put the PZ1 screws in one section and the PH 2 screw in another. I can’t tell which screw is what. I tried putting a pz1 bit on both screws and the pz1 head sits firmly on both so I’m even more confused. Can anyone help identify what screw is PZ and which is PH? Left to right ?

Thanks

 

[denso13]

They both look like PZ screws.

Pozidriv vs Phillips: What's the Difference?

Find out the difference between Pozidriv and Phillips screw heads. Discover why they are different and also how to identify the differences between the two.

shop4fasteners.co.uk

 

[john2k]

They both look like PZ screws.

Pozidriv vs Phillips: What's the Difference?

Find out the difference between Pozidriv and Phillips screw heads. Discover why they are different and also how to identify the differences between the two.

shop4fasteners.co.uk

That’s even more confusing. It’s a Geberit Infrared touchless flush sensor back box system that I need to install and it comes with 4 screws. Two short ones and two long ones and the instructions are illustrations only and I’ve attached the two reference it makes to the screws.

I’m assuming I need to go based on length maybe but it’s hard to tell which screws in the pic are longer lol

 

[denso13]

One is shown as pan head and one countersunk in the illustrations. Go with that, it is what you have in your hand.

 

[stevie888]

Seriously weird this: Phillips are the devil's work though as I can never find the right screwdriver when I encounter one!

If you look at the 2 diagrams the driver heads are actually drawn different!

The first pic to my eye shows the shorter one and the countersunkhead. You should see a countersunk hole in 1 location which would provide another tell.

 

[freddiemercurystwin]

Seriously weird this: Phillips are the devil's work though as I can never find the right screwdriver when I encounter one!

If you look at the 2 diagrams the driver heads are actually drawn different!

The first pic to my eye shows the shorter one and the countersunkhead. You should see a countersunk hole in 1 location which would provide another tell.

Agreed, does the head match the length of the screws in the pics?

 

[^woody^]

For the sake of four screws, use what ever fits!
Or as Mrs W would advise, a knife out of the cutlery drawer.

 

[stuart45]

Phillips screw heads are designed so that the Phillips screwdriver will cam-out (slip) if too much torque (power) is applied. The reason is that this prevents the risk of the screw head being twisted off by a power tool. This can be helpful, because if the head breaks off, a screw is very difficult to move.

Pozidriv screws, on the other hand, are designed specifically so that the screwdriver head does not cam-out.

Cut and paste from the article.
Bit of an urban myth that Phillips were designed to cam out. They were invented because they didn't cam out as easily as slotted heads.
They still do cam out which is which they are used for plasterboard screws.
Anyone who has used thousands of Pozidriv screws knows that they cam out as well, and Hex and Torz are much better for heavy stuff although a bit slower, which is probably made up in time by not wrecking the heads or bits.

 

[securespark]

For the sake of four screws, use what ever fits!
Or as Mrs W would advise, a knife out of the cutlery drawer.

Like this one of ours...?

 

[opps]

Seriously weird this: Phillips are the devil's work though as I can never find the right screwdriver when I encounter one!

If you look at the 2 diagrams the driver heads are actually drawn different!

The first pic to my eye shows the shorter one and the countersunkhead. You should see a countersunk hole in 1 location which would provide another tell.

Folk law says that Phillips screws were designed so that the head would cam out and reduce the risk of over screwing and ripping the threads. I have no idea if that is true though.

In the last few years, when working with cheap Phillips type screws provided with window locks from the East, I find that JIS screwdriver bits are far less likely to cam the screw head. I strongly recommend the Vessel ones. Not cheap but well made.

 

[stuart45]

It's untrue.
First rule with those goods is throw away the screws and use decent ones.

 

[opps]

First rule with those goods is throw away the screws and use decent ones.

Agreed, but as a decorator, I am often temporarily removing those fittings prior to repainting.

 

[stuart45]

I was asked by a customer to put up some blinds she got from Dunelm a few years ago. I reckon at least have of them snapped the heads off before they were even fully tight by hand.
I suppose the difference years ago was that the correct sized clearance and pilot holes were used, so even a slot head was easily screwed in and tightened up.
Nowadays we use impact drivers to get the job done in seconds.
A mate of mine who's a Thatcher, will only used Hex when fixing the thatch down. I'm not sure they even make Pozi for the fixings.

 

[Old Salt]

I always thought pozi screws had the little line between the head slots for the driver. So thise both look the same i.e. pozi

 

[opps]

I always thought pozi screws had the little line between the head slots for the driver. So thise both look the same i.e. pozi

You are correct.

As an aside, JIS screws have a little dot on them. The interwebs are full of motorbike owners (with Japanese bikes) who want to remove the screws without leaving visible marks on the screwheads. Through them, I discovered that Vessel are akin to the likes of Wera and Wiha quality wise.