It is told how to modify and sharpen household scissors so that they cut like hairdressers.
Under the microscope, you can see that the cut is the same even.

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I took old household scissors, which even cut paper poorly.
The cutting edges are very dull and, in addition, the blades are strongly curved. And for hairdressing scissors, the bend should be small.
Therefore, the first thing I decided to straighten the blades, to reduce their bend.
Unfolded in a vice.
Then he sharpened the blades of the scissors along the inner surfaces, which are the back. It was necessary to form a support surface.
I sharpened one blade on a cast iron lapping plate, and the other on a mirror. I used 28/20 grit diamond paste.
The blades must be held while lapping so that the cutting edge and the heel are lapped at the same time. Due to the fact that the blade is curved, it is necessary to press in the middle of the blade so that the touch goes along the entire length of the cutting edge. It is necessary to grind until a uniform continuous surface of support is formed along the entire length of the blade.
The cutting edge was made sharp by sharpening along the front surface.
One blade was previously sharpened on a grinding machine, and the other with a file.
After that, the surfaces of both blades were leveled with a homemade grinder. How I made the grinder is shown here:
   • ГРИНДЕР на базе  АВИАЦИОННОГО ЭЛЕКТРО...  
Finally sharpened the cutting edges with a fine-grained abrasive bar.
During preliminary sharpening, the angle of sharpening of the cutting edge was 40 °, and at the final - 45 °.
And finally corrected the cutting edges on the skin with GOI paste.
Collected scissors. Adjusted with a special screw with friction lock. How I did it is shown here:
   • НОЖНИЦЫ плохо режут. Фрикционное СТОП...  
Scissors cut hair easily, and the cut is even, as when cutting with professional hairdressing scissors.