Screws: Why Phillips & Flatheads?

Ok, this must be an age-old question. Why are there both phillips and flathead screws? I wager they were developed around the same time, and both stuck (i.e., stuck around over the test of time). But, I wager the phillips screws give a better gripping surface and perhaps better torque distribution therby making it a little easier on the carpenter?

This was covered, but can’t locate.

Phillips screws are easy to self-center a tool on. Slot-head screws can have very small (low profile), flat heads.

Much more to it, but that’ll get ya started. Note: square drive screws are very popular when torque is need. Hex and Torx-head screws are also in many applications, from full-size autos, to hobby-sized equipment, and all types of machines in between.

To anyone doing anything mechanically, you’ll see all ones I mentioned all day and night.

The general answer to this question is that you can’t get everyone to agree on what’s “better.” There are applications where each works better, so both types persist. There are a lot of other types as well, such as the ones Philster mentions, and one of my favorites, Pozidriv. Note that that Pozidrive page links to a page that explains what it means to “cam out”, and points out that Phillips screws were specifically designed to cam out, which is something I dislike about them.

Not sure, but I think slotted screws go back nearly as far as screws of any kind, whereas Phillips date from the creation of assembly lines. The slot is so easy to make that most mechanics have made them themselves from time to time with a hacksaw. The Phillips, on the other hand, is stamped in with special tools.

By the way, the slot or “+” shaped indent (or hexagonal hole or whatever) is called a “drive recess”.

Wiki claims the slotted form predated alternative types by about 400 years, which sounds about right to me:

Phillips screws came with more advanced automation processes specifically because they cause the screw driver to cam out. ie a machine or assembly line factory worker could not over tighten them. With a straight screw you can over tighten and shear off the heads. The cam out quality is preferred for applications like drywall and hinges.

In electrical they are going more and more to Robertson(aka square) drives.

Does no one read Cecil anymore?

Why did this guy Phillips think we needed a new type of screw?

[on-topic gag]
Q. How do you make a Phillips screwdriver?

A. Vodka, orange juice, and Milk of Magnesia

[/on-topic gag]

Thanks, all for the replies. I can’t buy the “you can’t cam out a Phillips” story, though. If that phrase basically means to overtighten, I can’t begin to count how many Phillips heads I have burred from overtightening.

For those interested in correct terminology (e.g., “flathead” was used incorrectly in the OP) about screw heads.

YOu got it exactly backwards. They were saying you can cam out a Phillip’s head.

The idea for Phillips cam-out in a production setting is the tool cams out before the screw breaks. And yes, minor damage is done to the screw head. That should be minimal to negligible if the tool is withdrawn properly when the camming out starts.

Notice that any installation damage is the customer’s problem, not the factory’s, and the damage impedes tightening next time, not loosening. So teh custoemr can still readily disassemble the item and a new fastener solves any problems with reassembly.

Also note that Phillips was state of the art stuff when invented. I’m not suggesting all the above is the ideal solution today.

I feel like I must point out that Phillips and a cross are two differnt types of screws, although I have gotten tired of correcting people about this in my daily life

Not sure what you mean by a cross. My understanding is that crosshead screws are a category which includes Phillips and Pozidriv, as well as several others described in this article. I would say that every Phillips screw is a crosshead screw, but not every crosshead screw is a Phillips.

I paid $5.00 at a garage sale for a kit that contains drivers for every screw head I’ve ever seen. Since they are made to be driven by a small ratchet, you sometimes encounter difficulty with space, but for the most part, that was the best $5.00 I’ve ever spent.

Robertsons are the best!

Too bad he didn’t want to license them to Ford

I learned about Robertson screws watching Holmes on Homes. He uses them on every job. They’re easy to buy in Canada. The heads don’t strip out like Phillips heads.

I like them for woodworking - the screws “stick” to the driver head so you can easily start them one-handed and you can generate a ton of torque when needed.

McFeelys ( sells a wide variety of Robertson (square-drive) screws, that’s where I order mine.

Quoted for truth.

Whenever I buy a piece of hardware that comes with the dreaded philips or gasp slotted screws they go straight into the trash.

The worst design seems to be the “universal” one we get stuck with on electrical devices here in the US. It is a combo slotted-Phillips-Robertson one, which strips out equally well with all drivers. Picture here.

The first time I saw a Phillips screw and driver (I was probably about 7 years old at the time), the first thing I said to myself was “why did they design it so the area with the most force applied has the least contact between the head and the driver?”