This is so irksome I have to rant. It’s those screw heads that have both a slot and a Phillips (or other crossed) drive recess. You often see them on electrical equipment such as terminals and strain reliefs. The most detailed descriptions I’ve found, on web sites serving mechanical engineering CAD users and fastener manufacturers, say the history is they were invented so that you can grab either a Phillips or a straight screwdriver, and they will work; but they also say that neither works well enough to torque the screws to typical specifications. So now they sell special “combination tip” screwdrivers just for these screws. In other words, in an attempt to let you use either of the two existing kinds of screwdrivers, they actually created a need to carry a third type, making matters worse.
I just had to do a bunch of these yesterday, on some very big connectors, and didn’t have the special combination tip screwdrivers. I spent a good hour or so making metal splinters with my straight screwdrivers, and camming out my Phillips screwdrivers, and threatening to drive a six inch screwdriver through my left wrist in the process. I think the mechanical design of things that serve electrical purposes might be pretty nearly the worst mechanical design you can find in industry.
I’m actually a bit surprised you didn’t head to The Pit for this.
As an electrician, I’ve had to deal with these on a regular basis. I advise others to do two things: Do NOT use a Phillips screwdriver on these, as they are virtually ineffective. Use the largest, broadest flat screwdriver blade you can. I have several flat screwdriver tips and some regular screwdrivers that work great. Never a problem. Just don’t try to use a medium flat tip for these screws.
They are horrible, and I’m not surprised Klein has a tool for them as I’ve only seen those bastardized screws on electrical devices and Klein is a generations-old maker of electricians’ tools.
If you have a JIS driver, that would probably drive them just fine. JIS is a Japanese standard that resembles Phillips except it is shallower and the drivers don’t cam out. If the screw has a little dimple on the head, it’s JIS. Using a Phillips on it is guaranteed to booger it up.
Want to make it worse? I’ve seen some of these screws that also can be driven with a Robertson driver. It’s just a matter of time before someone adds external Torx to the rim of the screw head. :eek:
I just got my special combination screwdriver bits. As you can imagine, their geometry is more complicated than a Phillips. They look like they’d be really uncomfortable to stab one’s eyes out with – but, then, now that I have them and should be able to use these screws without ruining everything, I’m probably not going to be inclined to do that anymore, anyhow.