All owners of hair cutting shears must know how to correctly adjust the tension on your beauty shears and barber scissors as well as grooming shears. Shears with a thumb-nut or knob style pivot screw are easy to become loose and must be tightened. Usually you can turn the knob clock-wise to tighten using just your fingers. Sometimes you may need to use a pair of pliers. The correct adjustment will allow the handles to move easily without slamming shut or wobbling. The key is to listen for a click on most of these screws as you turn the knob. Turn one click then check the adjustment. If you get too much resistance, soaking the screw in oil to loosen the threads that may become rusty is important because you would not want to strip the screw.
Stylists and barbers should watch this video to see how to correctly adjust the tension on their shears.
Sharpeners and others who are interested in more details on correct tension screw adjustment might want to watch this longer video.