Therefor it is exstremely important that the scissors is set correct and with the correct tension. When the scissor is made correct and tension is corrrect, the 2 blades will perform perfectly with each other without any side movements like when the tension is too loose. Scissors with correct set and tension adjustment can normally stay sharp for years and can get very old. A scissor with correct set and tension can easily get to be 15-20-25 years old if it is also maintained correct.
What is the correct angle for setting the tension.? There is not 1 correct answer to that. It depends on the quality and manufacturing of the scissor