why are there more than one screwdriver (or screw) type?

Factual Questions
21

[quote=“Gary “Wombat” Robson, post:19, topic:607058”]

More than one type of screw? Ever try to put a brass screw into a piece of ironwood? I’d hate to put together a deck without self-piloting screws. I like the ones that have a cutting edge on the bottom of the head to self-countersink, too.

There are round heads, flat heads, fine thread, course thread, machine screws, wood screws, brass screws, stainless screws, colored screws that match specific decking material, metal roofing screws with rubber gaskets, galvanized screws, screws with threads all the way to the head, and screws with plain shanks right under the head. When you can’t get a screwdriver to the screw head, you want a hex-head screw so you can tighten it with a wrench instead.

Some screws have heads designed to require special screwdrivers, and some that will only engage the screwdriver when being inserted. Some screws have no head at all, but only a hexagonal indent in the end of the shaft to take an Allen wrench.

The world needs lots of different kinds of screws!
[/QUOTE]

I’m not talking about the different types of screws… i’m talking about the head on the screw. i.e. how to screw it in and unscrew it when necessary.

So far, I’m not convinced yet that the world couldn’t live with just one style. If Torx have a benefit, fine. Make all the screws with a torx head.

Other than those security screws that permit the screw to be put in, but don’t permit the removal, there is no other application I can think of.

I’ll keep reading, but the best answer so far seems to be the tool manufacturing theory.

22

Well, there are justifications for multiple types, although I’m not going to argue that we really need ALL of them. For one thing, the simple slot design and Phillips head do not require a precisely sized driver - somebody armed with the one screwdriver they have handy in their desk drawer, on their pocket multitool, or a nail file, come to that, can manage to turn the screw. If you don’t have to screw something on very tight or precisely, and it’s likely that somebody with minimal tools is going to want access, this is an advantage. You don’t need a Torx head or something like that on a light switch cover. If you require being able to turn the thing without the driver slipping, etc, you will want one of those others. But you will have to have a set of drivers to properly fit the various sized heads.

23

They weren’t, actually.

24

Care to elaborate?

25

For the same reason we don’t all wear the same kind of shoes. Different situations require different benefits.

Phillips head screws, as already mentioned, are designed to cam out so as to prevent over-tightening. Pozidriv screws (which also have a + shaped slot and are commonly mistaken for Phillips) are designed not to cam out, for when you need to be able to tighten them with more torque. Hex head (allen key) screws work well with those little L shaped keys you get with flat-packed furniture, so they can be tightened in a confined space. And so on. If you use the wrong one, you either damage what you’re building or have it fall apart.

26

Okay. But that’s not what you said in the part of the OP that I quoted.

Your goal is to only have one or two screwdrivers? That’s a problem.

Torx, Robertson (square-drive), and Allen head screws all require a set of drivers in different sizes. You have to scale up with the size of the screw, or you’re going to snap off the shank of the screwdriver. Even with one standard head style, you can’t get away with just one or two drivers.

Flat-blade screwdrivers partially solve that problem, but they’re absolutely horrible to use with a power driver since they’re not self-centering and the heads tend to strip out easily. They definitely have their place, though.

Also, as I mentioned above, in a tight space, you may not have room above the head to fit a screwdriver. That necessitates either a hex-head screw or an Allen-head (although you could probably find a set of right-angle Robertson or Torx drivers).

I would be happy to see Allen screws replaced by Torx, and Phillips screws go away entirely. I just can’t see backing down to a single type.

27

If we had on one type, whos standard would we use, DIN (German), SAE (American), JIC ( Japanese)?

28

I recently ran into problems breaking loose an allen head set screw on a pulley. I could tell my Hex key was trying to twist and break. Even tried a small crescent wrench to turn the Hex Key.

That set screw was rusted in there. Finally had to buy an allen wrench bit socket for my ratchet set. That was strong enough to break the set screw loose without breaking the key.

29

What’s to elaborate? Peter Robertson (inventor of the eponymous screwdriver) was widely regarded as a harmless crackpot for the decade-and-a-half before Adolph Ketteruck of the Craftsman Corporation accidentally hit upon a manufacturing process for producing screws which worked with it.

30

I’ve had very good luck with Liquid Wrench in situations like that. Or even WD-40.

31

For the casual home handyman, the best screw shape I have ever used is the Robertson. It is available all over Canada, not so much in the US. It has a square slot, is pretty much self-centering, does not cam out, is just as efficient in going in as in coming out, and will not slip and damage the wood. I absolutely detest slot heads. Just too hard to work with. Why are they still used? Is there any job for which they are superior?

32

It’s gotten better. You can get those in just about any U.S. hardware store now. Several brands include a driver bit in each box of screws.

My only objection to the Robertson square-drive is that I seem to break the driver bits on the large screws. I was driving 4" screws into studs and snapped three of them (the bits, not the screws) in one day.

33

That sounds riveting. :rolleyes:

34

I’m curious about this too. Slot-head screws are still commonly sold in hardware stores as woodworking screws. In fact it seems that most of the wood screws I see are still slot drive (though other drives are not rare).

It makes sense that woodworking would be about the only place you’d still see them, since it’s one of the few jobs where manual screwdrivers are still commonly used. But that doesn’t explain why slotted wood screws are still so commonplace, since Phillips/etc are available and easier to use even for hand tools. Do slotted wood screws have an advantage, or is it just tradition and inertia? Seems to me they’re inferior in every respect.

35

slotted heads have the advantage that they don’t fill in. other head styles can corrode to make the bit not fit. other head styles can fill with dirt or debris. a slotted head can be rejuvenated or cleaned the easiest. if the screw needs to be removed requiring torque then a slotted has some advantage.

36

[quote=“Gary “Wombat” Robson, post:26, topic:607058”]

I would be happy to see Allen screws replaced by Torx, and Phillips screws go away entirely. I just can’t see backing down to a single type.
[/QUOTE]

I could live with that. While much of the time slotted screws are a pain to use, they are the most tolerant of the wrong size bit or old, worn ones. You also have a far better chance of getting old rusted or overtightened slotted head ones out. I cursed Chrysler mightily trying to get the Phillips head screws out to get the headlight rims off my car to replace the head lights. I had a notion to write Chrysler and suggest they rivet them on because the rivets would be easier to drill out.

Most of the screws my Ace Hardware stocks now are the dual slot/Phillips head ones. The ease of installing Phillips and the better chance of ever getting one out of the slot.

Phillips aren’t too bad for high volume things like drywall that you never expect to remove. One of the worst things about Phillips heads are the like of Reed and Prince heads. Indistinguishable except the bits and screw heads don’t work as well. Fine at the factory where the screws come in a box telling what they are.

Decorative? The dash of my 81 Phoenix was put together with Torx screws. It also had additional spots molded to look like screw heads. I figured all the Stars of David were telling OPEC. ‘‘up yours’’.

Oh, can we stake down whoever decided we need reverse Torx heads to an ant hill?

37

Only if they’re red ants.

38

Thanks johnpost, that makes perfect sense.

39

Yes it does, actually.

40

I don’t want to cry “Cite!?” but…I’ve never heard of this in my life, and would like to learn more. Can you show me a source or example of this being done?