Earnest Botello Loc: Hockley, Texas

I work on and build computers, so the P nut driver hillips head and nut driver screws are a must. You don't dare use a slotted screws inside a computer, one slip and you might ruin a motherboard or other components. The Phillips head, nut driver combo are best.

DaveMM Loc: Port Elizabeth, South Africa

The problem is that there are Philips and Pozi, which are a much better development of Philips. All the chipboard screws I use are Pozi, but all (at least all I've seen) screwdriver sets supply Philips which are even worse in a Pozi screw. I always buy the correct Pozi manual screwdriver or bit for my electric screwdriver, and don't have any significant problems.

whfowle Loc: Tampa first, now Albuquerque

I believe it is more a matter of history than engineering. In the beginning, it was easier to make a slot. Today, the best are neither slot or cross head, but various forms of internal polygon such as hex or torx.

Triple G

Great advice for the garden and kitchen, too.

Abo

Phillips, the excellent JIS cross, or recesses that are square, allen, torx,
are a PITA when painted... stopping the tool entering the cavity when
it comes time to remove them. A slot for a plain screwdriver is
far easier to remove paint from... a swipe with the blade of the plain screw
driver, job done.

Many ag planes have slotted screws for much the same reason... farm chemicals filling the recesses.

Otherwise, give me a recess too.

Harold Stetson Loc: Marquam 97038

What I like about Torx is there is one type. They are numbered and if you get the right fit they handle an amazing amount of torque. Allen will round off and comes in SAE and Metric both. That means two sets and you always have the wrong one. One set of torx is enough. Phillips works well in aluminum where it sticks. If the screws are good quality and the fit is correct it allows use of an impact driver and that can apply amazing amounts of torque along with the impact of hitting the screw it works well. A slot works well for low torque stuff to snug it up and not torque it and clean it out, dig out the paint and still work. The trouble is you can't fix stupid and we all go there some times.

Jack 13088 Loc: Central NY

It beats me. There is the expectation that the ultimate consumer only has straight bladed screwdrivers. I have over time accumulated straight blade, Phillips, Pozi (looks like Phillips but isn’t), Robertson (square drive), Torx (star drive), and Hex Screwdrivers and drive bits. Any can be damaged by cam out from over torque and/or using the wrong driver but it seems with the slot it is inevitable. Another beauty of the slot is the driver slips out and mars the work. For years brass screws in furniture hardware are Phillips to avoid that. I, however, can still ruin newly finished pieces.

I notice electrical wiring devices have transition a few years back to square drive or combination slot/sq drive fasteners. Presumably because they stick to the driver during insertion or removal from confined areas. However, they rescued defeat from jaws of victory with the screws on cover plates!

Jack 13088 Loc: Central NY

Pozi can be easily distinguished from Phillips by four hash marks halfway between flutes on the head. I first found out what they are because they are used extensively on Eurofasteners used in cabinetry. These have the brilliant feature that if you use the driver for one on the other you will probably destroy the fastener and/or the the driver and will certainly destroy your karma.

My 1950 MGTD, which is a horror museum of fastener types has some very large Pozi wood screws.

Harold Stetson Loc: Marquam 97038

One thing I forgot to mention was flat works well if it is good quality and a good quality screw driver is used that fits the slot. Early Chevrolet 6 cylinder engines came with slots in the pan and on the front cover. Large head screws with quality slots and either lock washers or star washer under. They didn't torque enough to get any stretch so the lock or star kept the tension as set. Make any of this crap low quality and you will have problems. Phillips that rounded into the grooves instead of being crisp and clean. Soft metal and poor quality in general. The workmanship of the 30s and 40s was amazing in many cases. That changes the rules from what we see today and wonder about quality when a machine makes a 100 a minute and dies get worn.

TriX Loc: Raleigh, NC

Do you still have the TD? Refresh my memory, is it metric or whitworth? (my “A” was metric).

chasgroh Loc: Buena Park, CA

Yanno, merits of this or that really reflect personal preference. For the hobbyist I would think anything would work with some TLC. But as a pro who does all kinds of work I really dislike flat heads. Very difficult to control with drill motors, whereas phillips, with all its inherent problems, is just flat easier to work. You have to know the correct bits to use, and many techniques gained over the years, but out in the field *most* guys use phillips. That said, I'm a fan of square drive and will use them on individual cabinet projects...and out in the field *especially* if I know who's gonna follow me so I can mess with 'em, haha. Seriously, tho, I notice at the big box stores they seem to be pushing the star configuration, which is an OK system but just adds to the "goddammits" in the field. ;0)

Red6

As a retired manufacturing engineer, my best guess would be production costs. The making of a slotted screw is probably the cheapest and easiest of all the fasteners made. Their use is declining but I think they will be around a long time to come.

Another factor could be the wide availability and use of slotted screwdrivers. I would hazard a guess that there is at least one slotted or phillips screw driver in almost every toolbox or home in the US. While many people may own a few screwdrivers, there are probably many of those same people that do not own an electric driver of some type. Those other types such as square, torx etc would be found only in someone's specialized tool box or someone involved in higher production levels such as a carpenter or cabinet maker.

There may also be some technical reasons also. A lot of very small screws seem to be slotted. It could be that on very small screws there is not enough room on the head to put any other type of opening such as a phillips, torx or allen head. For example, the screws on eyeglasses for the most part seem to be slotted.

chrissybabe Loc: New Zealand

Very simple. There are three reasons.
1. Most people are very reluctant to change anything. From when they were a child they saw screws with slots. So that gets set in their minds and they use them for the rest of their life. They want a screw, they go to the hardware shop and see 6 different heads but still pick the slotted variety. Or they are replacing a screw so use what was there beforehand (which probably was because the previous 'screwer' choose the cheapest).
2. Follows on from 1. The shop buyers see lots of screws go out the door so buy more of the same - with slots.
3. Follows on from 2. The manfs see slotted screws selling well so keep making them.
Now this is my opinion only. Buyers in 2. above and manfs in 3. above and users in 1. above are basically thick.

This is how I do it. Applies to wood screws and engineering screws. Does not include specialist things like high tensile or set screws.
1. How long do I want the screw to last. Usually quite a long time. If you don't need a serious lot of strength (or go next size up) buy stainless steel screws.
2. What type of head do I want on the screw. My choice is from most preferred to least - torx, square, pozidrive/hex.
Lots of things can alter that. Size available, not knowing the right source, head type.
You can buy all the screwdriver tips mentioned above so the actual tool is not an issue.

If the job is worth doing at all then do it properly !

starlifter Loc: Towson, MD

I volunteer at a museum. When restoring an old fire truck I would never ever use a philps head or torn screw torque or not.

Mark-VA

The square drive is Robertson. As Jerry said they're popular in Canada and also in the US in the cabinet and RV industry. They work quite well. I follow a YouTuber that does home repair and renovation and he frequently complains when he comes across a Phillips screw. He loves the Robertson square headed fasteners.