Standard conduction testers are similar to screw driver in having metal pointer and plastic handle but the head is made up of metal cap and a bulb inside. Why are they made so?
Answers
Explanation:
There are already answers to this questions and some of the are not quite correct and the most obvious which most have correct is the cost. It is easier to mold a plastic handle onto a molded metal shaft and the plastic can be molded into shapes that give a better grip. This is done quickly and cheaply. It also provides for electrical insulation so that doing electrical work and thermal insulation from the cold. There are metal handles with knurled metal handles but these are not very common are are more expensive. Very small screw drivers are also commonly made of steel blades with aluminum handles that are stamped. Yes, you can still buy wood handled screw drivers as well. The same goes for other wood working tools. Now it is getting to the point where everyone wants gadgets, so it is more common to see a multi-purpose tool driver that uses a power grip or a motorized power grip. These of course must be made of an injection molded plastic material, like ABS. So, just another answer as some of the others have pointed out.