Cross-Head, Cross-Point, Cruciform, Square Drive Screws and Drivers
instructables.com
instructables.com
The slotted terminal screws worked well because they were cheese head, or cylindrical, allowing the driver to apply torque at the very edge of the slot. Outside the Bell System, terminal screws are usually binding head, which has a fillet around the top edge, removing material where it's most needed.
(Pro-tip: IKEA never uses Phillips screws. They’re exclusively Pozidriv. Get yourself a Pozidriv driver and assembling their furniture becomes an order of magnitude easier and faster.)
Here's a Google image search for "ikea screws" showing a selection: https://www.google.de/search?tbm=isch&q=ikea+screws
But I know what you really meant ;) - there really are an insane amount of heads covered in the article, and it doesn’t even scrape the top of the barrel.
Relevant XKCD of "now there are eleven standards".
[1]: https://blog.hubspot.com/marketing/scrolljacking-the-good-th...
I am, however, ashamed that I wasn't aware of all the Phillips variants. That would explain why I was drilling out screws last week!
I really enjoyed that article.
Essentially, it was a bolt that had an integrated electro-mechanical locking mechanism, plus a microcontroller.
The idea was that these bolts could be used in places where you wouldn't want them to be removed by just "anyone". One example was head bolts on a car (you can imagine how well that went over).
To remove the bolt after it was put in place and "locked" would require a special device that would apply power and a required code to the controller, to cause it to "unlock". Likely this device would be a special kind of wrench or socket.
Now, I could see such a device in certain cases - for example, lamp posts or traffic signs (though how often have you heard of people just removing those bolts?). But the application almost always illustrated had to do with cars; that manufacturers would be able to restrict access to repair to only dealers and no one else.
I'm not sure if this was why they never were created or not; maybe. I tend to think, though, that the complexity of integrating the required locking mechanism into a bolt while simultaneously ensuring its integrity and strength (especially in the case of say, head bolts), probably was more a factor in it.
One is from http://help24center.com and is dressed to look like some kind of official or system alert from Apple.
> When I wrote this "ible" the original intent was to stick to Phillips look-a-likes. It grew to this.
> Due to input and interest shown by readers, I'm already working on a sequal, or re-write to include combo drives, security drives, and incorporate comments and new pictures.
The Phillips system was invented for use in assembling aluminum aircraft, with the object of preventing assemblers from tightening screws so tightly that the aluminum threads strip. The driver will cam out before that happens. ... Phillips is designed so that when excess torque is applied it will camout rather than ream the recess and destroy the bit.
It's not a bug that the screwdriver keeps slipping out when you are struggling to make that last quarter turn at an awkward angle, it's a feature!
The application that really showcases what TFA calls the "camout" feature is drywall. A drywall installer will keep the screwgun turning, and every time he punches the gun into the drywall, a new screw is pushed off the belt. The screw is driven until the gun hits its stop (a sliding mechanism that controls how close the gun can get to the drywall) and the screw naturally slips out when it's at the proper depth. This is important because drywall is quite fragile and otherwise it would be easy to drive a screw too far.
Except that wasn't really the reason. The reason was to prevent the keys from jamming (by locating common letters and sequences of letters away from each other); the fact that it tended to slow typists down was only a side-effect.
Still sucks to accidentally strip a screw that really should be that tight!