Care of Screwdrivers
Carl Kammerling International has developed an optimum balance which gives great performance, but it is still possible to break the screwdriver tips.
How do breakages occur?
Using a screwdriver that's too small for the screw size is a surefire way of breaking the screwdriver tip.
The blade only contacts the screw slot at both sides and the user will need to apply a lot of torque to turn the oversize screw.
In the diagram on the right you can see the limited contact points.
Inevitably this will cause the blade to break at the edge - like this one:
It's the same story for cross head screwdrivers:
Here the blade only slightly comes into contact with the screw and again a lot of torque is transmitted through very little screwdriver blade material.
Because of the additional 4 points on a PZD screwdriver, it will not fit a Phillips screw correctly, and is likely to slip or damage the screw head. Phillips screwdrivers will fit in and turn PZD screws, but will cam out if enough torque is applied.
Modulo screwdrivers are particularly sensitive to the right size being used in the right screw.
As you can see in the diagram on the right, there is very little blade contact with the screw and damage to the screwdriver is highly likely.
The other thing worth mentioning here is that if you use a screwdriver that is too small, you wont get the right torque on the screw and this can be potentially dangerous.
For an electrician, loose connections are the last thing needed if shorts and fire hazards are to be avoided.