5 ms·

Here in the UK most new screws are Pozidriv, but many people confuse them with Philips as they are very similar. Mixing up Pozidriv/Philips results in the drive

Here in the UK most new screws are Pozidriv, but many people confuse them with Philips as they are very similar. Mixing up Pozidriv/Philips results in the driver riding out and damaging the head. It should be required teaching in schools the difference between the two! Pozidriv screws have a small engraved cross at 45 deg to the main recess. The drivers have a small matching flute in the grooves. Nice picture here: https://www.finehomebuilding.com/2015/09/16/what-is-the-difference-screw-bits-phillips-vs-pozidriv https://www.finehomebuilding.com/2015/09/16/what-is-the-diff...

ungawatkt 4y ago
Imo that's the main failure of the posix, it _looks_ like a Phillips, and behaves like one of you use a Phillips bit. Which is rather unfortunate and not really it's fault, but hard to overlook for "normal" usage.
- xen0 4y ago
  A little harsh to call an intentional compromise 'a failure'. A feature is that pozi is compatible with Phillips bits, just without its advantages. For people with older or smaller toolkits, that's actually quite helpful.
__alexs 4y ago
Pozidriv exists almost entirely because the old patent expired. It is not sufficiently better than Philips that the overall fastener situation is improved by its existence.
alkonaut 4y ago
PZ are useless as a standard because it's not significantly different enough from others, and you can't tell which PZ you need. Torx and hex is brilliant because you can easily say which shape of bit you need, and you'll instantly know if you pick the wrong one. Luckily Torx seems to have finally won and screws that require any kind of moment (construction/decking/fasteners/) now seem to use them in stores, while only the kind of scre you'd hang up a picture frame with is PH/PZ. I have never seen a square (Robertson?) screw in the wild, I assume that's regional.
- mc32 4y ago
  I see Robertson on Decks/Decking mostly --they are stainless or rust resistant so their necks/shanks don't weaken over time. Others rust and when you try to take them out they shear off easily.
- darkerside 4y ago
  Worse than useless, that makes them actively harmful. I'm glad I know pozidrive now.
- cout 4y ago
  Most of the cement board screws I've used (for installing shower tile) are square head; I've not done much shower work so I don't know if that's a trend or just what the store has at the time. My fleetwood mobile home built in the late 90s was assembled entirely with square head screws, hex head lag bolts, glue, and a lot of staples.
- rsync 4y ago
  "I have never seen a square (Robertson?) screw in the wild, I assume that's regional." Simpson makes very large diameter, 4" stainless steel screws that I rather like: #12 x 4", model number is S12400DBB ... those are 306 stainless but if you want 316 you would get T12400DBB. IF we use screw fasteners in framing, we typically use GRK 3-1/8"-#10 but once in a while we just want something beefier and those simpson 4"-#12 are fantastic ... ... and they are square drive.
  - Zobat 4y ago
    Being from Europe (Sweden) I can't remember having ever seen a square drive screw. Torx is slowly becoming the standard here.
  - alkonaut 4y ago
    We get some Simpsons stuff in Europe (like nail plates and beam hangers) but I don’t think the screws are sold in Europe. If they were I don’t think it would be very easy to introduce a square bit screw in s as market where they are unknown. And obviously, not much uses any imperial naming. I think this is regionally produced because e.g a beam hanger for 45mm timber has to be pretty close to 45mm and a 2” won’t do.
xen2xen1 4y ago
Holy crap, is that what PZ means on all my bits? No wonder they don't really work right for Phillips.
- seattle_spring 4y ago
  I'm having the same revelation. Just setup a kit that had about 100 pz screws. The whole time I was thinking "man these screws suck!"
IshKebab 4y ago
Pozidriv screws are definitely better than Philips but they're still pretty awful. They're basically the second worst fastener in common use.

ungawatkt 4y ago

Imo that's the main failure of the posix, it _looks_ like a Phillips, and behaves like one of you use a Phillips bit. Which is rather unfortunate and not really it's fault, but hard to overlook for "normal" usage.

xen0 4y ago
A little harsh to call an intentional compromise 'a failure'. A feature is that pozi is compatible with Phillips bits, just without its advantages. For people with older or smaller toolkits, that's actually quite helpful.

__alexs 4y ago

Pozidriv exists almost entirely because the old patent expired. It is not sufficiently better than Philips that the overall fastener situation is improved by its existence.

alkonaut 4y ago

PZ are useless as a standard because it's not significantly different enough from others, and you can't tell which PZ you need. Torx and hex is brilliant because you can easily say which shape of bit you need, and you'll instantly know if you pick the wrong one. Luckily Torx seems to have finally won and screws that require any kind of moment (construction/decking/fasteners/) now seem to use them in stores, while only the kind of scre you'd hang up a picture frame with is PH/PZ. I have never seen a square (Robertson?) screw in the wild, I assume that's regional.

mc32 4y ago
I see Robertson on Decks/Decking mostly --they are stainless or rust resistant so their necks/shanks don't weaken over time. Others rust and when you try to take them out they shear off easily.
darkerside 4y ago
Worse than useless, that makes them actively harmful. I'm glad I know pozidrive now.
cout 4y ago
Most of the cement board screws I've used (for installing shower tile) are square head; I've not done much shower work so I don't know if that's a trend or just what the store has at the time. My fleetwood mobile home built in the late 90s was assembled entirely with square head screws, hex head lag bolts, glue, and a lot of staples.
rsync 4y ago
"I have never seen a square (Robertson?) screw in the wild, I assume that's regional." Simpson makes very large diameter, 4" stainless steel screws that I rather like: #12 x 4", model number is S12400DBB ... those are 306 stainless but if you want 316 you would get T12400DBB. IF we use screw fasteners in framing, we typically use GRK 3-1/8"-#10 but once in a while we just want something beefier and those simpson 4"-#12 are fantastic ... ... and they are square drive.
- Zobat 4y ago
  Being from Europe (Sweden) I can't remember having ever seen a square drive screw. Torx is slowly becoming the standard here.
- alkonaut 4y ago
  We get some Simpsons stuff in Europe (like nail plates and beam hangers) but I don’t think the screws are sold in Europe. If they were I don’t think it would be very easy to introduce a square bit screw in s as market where they are unknown. And obviously, not much uses any imperial naming. I think this is regionally produced because e.g a beam hanger for 45mm timber has to be pretty close to 45mm and a 2” won’t do.

xen2xen1 4y ago

Holy crap, is that what PZ means on all my bits? No wonder they don't really work right for Phillips.

seattle_spring 4y ago
I'm having the same revelation. Just setup a kit that had about 100 pz screws. The whole time I was thinking "man these screws suck!"

IshKebab 4y ago

Pozidriv screws are definitely better than Philips but they're still pretty awful. They're basically the second worst fastener in common use.