A screwdriver, plunger, drain wrench and cable auger are plumbing tools needed to fix a tub drain. The application of each of these tools depends on the type of tub drain and the problem encountered.
The most common problem faced with a tub drain is clogging. Most tub drains have a drop stopper with a setscrew below the cap. Lift the stopper and slide it off the shaft after loosening the screw with a drain wrench. If hair has collected on the crossbars, remove it with a cable or piece of wire. If the drain is still clogged, use a plunger to clear the pipe and replace the stopper.