What is Pozi screw?

Frank

First ran onto these screws about 30 or more years ago. There are available screwdrivers and tips but the heads of the screws seem to lack sufficient robustness to take much activity. The heads are easily stripped.

Some of the PoziDrive screws can accomodate some Phillips tooling and others simply don't take easily to any tooling. When I have the opportunity I dump the screws and replace with conventional Phillips heads. Preferably SS screws.

Funny thing is the Tektronix used them with their test equipment, oscilloscopes and the like, which gave them a bad name at times.

Hwev you tried a Google search for more information?

Bob AZ

Here's a brief discussion

Well, the heads are easily stripped *if you use a Phillips driver*. Use a Pozidrive bit and the chances of stripping the head or of the screwdriver camming out are much smaller.

Over here in the UK Phillips is almost dead, Pozidrive is everywhere (and is also a Phillips patented design) and square drive screws are a rare novelty (although well-regarded by people who've used them).

Try using the correct tools.

Try using the correct tools.

Pozidrive was developed as an improvement on the Phillips or crosshead screw. However, it is different from Phillips and works better when used with the correct driver. However, it's main disadvantage is that it looks like a Phillips screw and many Phillips drives also *fit* the Pozidrive head. The result is stripped out screw heads. Here is a more detailed explanation:

It's too bad that square drive is not common for you. The square drive has a bigger advantage over Phillips than Phillips has over a Straight blade screw. With Square Drive, srtipping out is almost unheard of. Additionally there is a Combo Square drive that lets you use a Phillips or Square drive driver.

A lot of these screw designs come from guys who want to use several thousand of them per hour via an auto-feed screw machine in mass production assembly. Robertsons don't work well in auto-feed. The square drive CAN be exactly 45 degrees out of place, and the machine will jam. So, for manual work, square (robbies) it is for me. But I always have tips and drivers for Pozi as all the euro hinges use them and a Phillips just plain sucks in a Pozi screw. McFeely's combos are just fantabulous.

A lot of these screw designs come from guys who want to use several thousand of them per hour via an auto-feed screw machine in mass production assembly. Robertsons don't work well in auto-feed. The square drive CAN be exactly 45 degrees out of place, and the machine will jam. So, for manual work, square (robbies) it is for me. But I always have tips and drivers for Pozi as all the euro hinges use them and a Phillips just plain sucks in a Pozi screw. McFeely's combos are just fantabulous.

These [GRK] puppies get my vote. AND, They're CANADIAN!

Dave in Houston

Thanks for the info. I currently probably have 3-4,000 square and combo screws from McFeeley and Kreg. I have had pretty good luck with both brands. I have regular square drives that have been outside for 15 or so years with the head facing up. They still are in pretty good shape even though the heads fill every time it rains.

Torx is a great screw. I recall using them way back in the late 70's when the automotive industry started converting over.

The whole idea of Pozi is that the heads are LESS likely to strip. Having said that, every screw with a head made from potmetal strips relatively easily. I'll take a hardened-head phillips screw over a mild steel pozi any day, but metals being equal, and the *right* tool being used, pozi is superior.

-P.

This is not my experience and I have never seen any evidence that square head is better performing than Phillips. In practice, I find little difference between the square drive and Phillips in terms of stripping out. Given the choice, I would pick the Phillips over the square drive.

This is not my experience and I have never seen any evidence that square head is better performing than Phillips. In practice, I find little difference between the square drive and Phillips in terms of stripping out. Given the choice, I would pick the Phillips over the square drive.

Oh GOOD LORD you must be charmed!!!

Sounds more like very little experience with Robertson screws.

Not at all. I am based in Toronto so most of the screws I can readily buy are Robertson. Now I know Canadians are very proud of Robertson and promote it wherever and whenever they can - just like Canadian beer. I have all the correct drivers for my drills and all the correct screwdrivers. The screws I buy are from all the major retailers here and a variety of manufacturers. The applications have been woodworking projects, deck construction, home renovation etc. Where I have the choice I will reach for the Phillips or the Phillips/ Square combo in preference to the Square.

Where's the evidence for your statement? For example, and I know it's a slightly different application, if you walk into a Rona or Canadian Tire looking for drywall screws, you won't find square heads at all - they're all Phillips! I worked on a large (tens of thousands of screws) playground project and the screws supplied were Phillips. The pros on the job bitched and moaned but when the job was done they begrudgingly admitted that they were not as bad as they thought.

That's what you like and what you're used to. Who am I to try to change your opinion? But, you *are* very much in the minority when it comes to what's most popular and what contractors like to use.

Your first argument I accept completely - the Robertson drive is much better at holding the screw than the Phillips, horizontally or vertically. On your second point, my guess would be that there is more contact with the Phillips. Anyway, as I work and live here in Toronto, I will just to learn to embrace and love the Robertson square drive because that is what is generally available. Maybe if I change my attitude to it, it will work better for me :)

Over 30 years of personal experience and my knowing a good half dozen contractors who I've worked with and who are friends of mine.

Drywall screws are and always have been in a category of their own.

You're supporting my argument by that statement. I never said there was anything wrong with Phillips screws, just that most prefer Robertson if they're available. Try a little experiment and use non-magnetic Robertson and a non-magnetic Phillips screwdrivers. Put on a screw and shake each one including turning them down. Almost always the Phillips will drop off first. It makes plain logical sense what's going to be more popular when they're examined side by side. It's also a fact that Robertson screwdrivers contact more screw head surface making them more capable of keeping a screw straight when driving it in.

One thing I do not deny, is that there are junk Robertson screws on the market. ~ Maybe more than there are junk Phillips. All things being equal, if I had to choose between cheap Robertson and cheap Phillips screws, I'd go for the Phillips every time. Cheap Robertsons don't hold as well and will strip much easier than the Phillips.

Where's the evidence for your statement? For example, and I know it's a slightly different application, if you walk into a Rona or Canadian Tire looking for drywall screws, you won't find square heads at all - they're all Phillips! I worked on a large (tens of thousands of screws) playground project and the screws supplied were Phillips. The pros on the job bitched and moaned but when the job was done they begrudgingly admitted that they were not as bad as they thought.

The reason that you don't see square heads on dry wall screws is because every screw is suppose to slip/cam out when the screw has reached the proper depth.