So, I’ve been seeing “Phillip’s head screwdriver” a lot recently. I’d just like to point out that it makes no sense. Phillip did not lend his head to a screwdriver. He probably wouldn’t like it if you thought his head looked like the head of a Phillips screwdriver either. So…stop calling it a Phillip’s head screwdriver.
Also, Phillip had nothing to do with the develop of the screw and screwdriver. The screw and subsequent screwdriver were developed by Henry F. Phillips. He supposedly developed it so that it would be harder for your to strip the head of the screw. Have you ever noticed that the Phillips screw cruciform isn’t neatly square but kind of has a rounded center? And have you ever noticed that a Phillips screwdriver has a fairly steep slope on the driver head? That’s so your screwdriver will cam out when the screw has been driven home (or otherwise stalls). The feature isn’t as important now since most power tools have torque limiters on them.
Thus, you could possibly call the screwdriver a Phillips-head screwdriver, but definitely not a Phillip’s head screwdriver.
Oh, and the Frearson screw and driver aren’t the same as the Phillips screw and driver. You’d think you’d realize this by the name. And you probably do…but can you tell by the head type? The Frearson has sharper and more defined edges so that the driver is less likely to slip out at high torque. Because it wasn’t designed to do so. Unlike the Phillips.
So now you know.