eschoendorff
Well-known member
I pulled out a bunch of #2 Phillips screwdrivers today and tested how much torque it took for each to cam out of the head of a new drywall screw. This is very subjective, but from best to worst:
- Lots of torque: Klein 5-1 screwdriver, DeWalt bit, Ace Pro screwdriver
- Moderate torque: Ace screwdriver (looks very worn)
- Low torque: Craftsman clear handle screwdriver
Everyone here says the Craftsmans ****, but I was surprised at just how bad it was. I think that having quantified tests would be useful for someone like me who hasn't tried all the fancy screwdrivers out there. I didn't believe that Craftsman was so bad until I tested it myself. I don't disbelieve it when someone says "Craftsman screwdrivers are bad," or "Snap-on is so much better," but having numbers would really help because it's a much more objective measure.
I got thinking about how to set up a testing rig. It's pretty crude and could use some improvements, but I thought I'd share anyway to see if maybe it'll inspire someone else to make something better.
In the first picture, you can see how to put a set amount of downward force on the screwdriver. I used a Craftsman drill guide to make sure the pressure on the screwdriver goes straight down. Instead of my hand pushing down on it, there should be a set weight. Also, the springs should be removed from it (I was too lazy to actually do that). The clamp on the screwdriver handle is used to prevent it from turning -- it hits the support post when you turn the screwdriver.
The second picture is actually from an earlier attempt at this, before I realized that the drill guide didn't go high enough to fit most screwdrivers. The screw is a machine screw with a washer on the top side and two nuts locked against each other on the bottom. (I should have used a longer screw, but this is all I could find.) The beam-style torque wrench goes on the lower nut and you turn it and measure when the screwdriver cams out.
A couple notes:
- Even when you're not pushing against the springs of the drill guide, the thing has a fair bit of friction, so it might be better to just dispense with the drill guide and stick a weight right on top of the screwdriver, using the hole in the upper piece of wood to keep it vertical.
- It's hard to get a lot of torque on the nut, so probably a bigger screw and nut should be used.
- You would need a more sensitive torque wrench than the one I have here.
You could use a similar rig to test durability, perhaps camming out the screwdriver a fixed number of times with a fixed weight, then test cam-out torque with a new screw.
It looks like you are on the right track....
