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I feel like a + shaped screw head would be as standard as a pyramid if multiple civilizations had developed screws independently. It wouldn’t be the last kind, but it would be there somewhere. Maybe even a long, long time ago.
There are at least 3 standards for the + shape already. Phillips, Pozidrive, and Japanese Industrial Standard (JIS). They do not play well together.
insert obligatory xkcd standards reference
Don’t forget Frearson/Reed & Prince!
But wait, there’s more!
And even more!
We only have standards so we can break’em.
JIS has been obsoleted and replaced in Japanese products with the ISO Phillips bit shape. It still exists on lots of products pre 2000 though.
Kawasaki is still holding on strong to JIS screws in it’s machinery.
Are you sure they’re JIS? Because JIS and ISO are interchangeable and effectively the same; the ISO adopted standard used most of JIS’s rules.
Yeah. I keep one of these around just for older Yamaha and newer Kawasaki equipment. You’ll end up drilling half of them out if you try to use #3 ISO.
I’m in the powersports/agricultural industry, so we tend to lag behind everyone else.
That’s just galvanic corrosion from using cadmium plated bolts in aluminum fuel injection hardware. It’s basically free loctite.
This bugs me so much more than it should. Why do we have three different standards for + shaped screws? You know what doesn’t have this problem? Flatheads. There’s exactly one way to make a flathead screwdriver, and I won’t be looking it up to make sure I’m right
I see that multiple people have replied, but unfortunately reading these comments would be a form of research so I must decline
Should the slot be partial or go all the way through? If partial, is that standard for the size of the screw, or universal?
How wide should the slot be? Should that change based on the size of the screw?
How deep should the slot be?
Should the sides of the slot be perfectly straight, or angled to perfectly fit the wedge shape of the driver? If angled, what angle?
Should the bottom of the slot be perfectly flat or slightly rounded so a coin or something could be used in a pinch? If rounded, what radius?
Should the top of the screw be perfectly flat, or domed, or raised?
Should the bottom of the head be flat, angled (at which angle), smooth, rough.
Should we use metric or freedom units for the thread pitch?
Should the threads go all the way to the head?
Should the point of the screw be flat or tapered (at what angle)?
Ok, only the first half of those were about the driver used, but I’m sure there are things I missed in that!
Their isn’t one way to make a flat head screwdriver. Some a chisel and some are slots. The slotted ones are better but more expensive.
Both still slip from the screw and are a pain to manually screw (slotted less so).
Pozi is the best + type screw. It’s pretty much standard for UK construction. The only time a different type is used is sometimes Phillips for plaster board or external hex and internal torx for long or large screws.
I think a single slotted screw head would be more universal and easy. You just cut one line into the top of the screw head and your ready to go. A Philips head would need to be cut twice and once you did, you’ve weakened the head one degree more by removing more material
You clearly haven’t had to screw a flathead screw.
Anyone that’s dicked around with those little bastards starts hating life after about thirty seconds. A fastener I can screw in a without having to be perfectly in line with the shaft? Yes please! I don’t care if it’s a shitty Phillips screw, sign me up. I’d even take those goofy square Canadian screws. Hell, anything is better than flathead.
I challenge you to find a screw worse to use than a flathead screw.
In my experience, Phillips heads strip more often than Robertson.
Torx > Hex > Robertson > Pozidriv > Phillips > Slot.
This is not (just) the ramblings of a mad nerd, but objective fact derived from contact area between screwdriver and screw.
In practice hex does have one situational advantage over Torx, namely that they are almost always tightened with Allen keys which are more torque-y and can be used in tight spaces. For every other application Torx wins. Every other head type is strictly inferior and only exists for legacy or penny-saving reasons.
What they don’t say is that the smaller the features on the contact, the easier it is to strip them. This almost reverses the order on your post depending on the way you tighten the screw.
For hex yes, for Torx no. Your smartphone’s itty bitty screws are quite possibly T4 or similar.
Torx is more resilient to over-torsion than Hex, but both of them will end near the end of the list on that one metric, with slot first, and way ahead of anything else.
Despite what the Torx publicity says, engineering is done over a multitude of dimensions, and that one dimension Torx wins may not be nearly as important as some other random one.
