As a rule, two individual blades must be sharpened when shearing. Due to the mutual interaction in the clash during the cutting process, an independent sharpening is not enough. In small scissors such as nail scissors, the joint sharpening effect is particularly evident.
Check the axle bolt first
A pair of scissors has two wings that move crosswise. Before sharpening, it should be checked whether the axis of rotation, usually a screw, is firmly tightened. If the screw has loosened, the blade distance of the scissor blades changes automatically.
If the two blades are not in an optimal position, even sharp blades may appear "dull" during use. The cutting sharpness and cutting ability depends on the blades and the exact clash. Before sharpening, the hinge screw should be checked for proper fit.
Sharpening scissors blades individually or together
The construction of the scissors allows two ways to re-sharpen the blades. The simpler way is to take advantage of the movement mechanics of the scissors. The cutting of a tool acting on the blade cutting tools is sufficient.
The scissors can be mounted for a more elaborate and, if necessary, sharper grinding. The two individual blades are ground like knives. According to the existing cut the angle must be adjusted when sharpening. A peculiarity of the scissor blades is the chamfer, which is always beveled on one side only. Under no circumstances should it be damaged on the inside of the blades, which will come into contact when using the scissors. More important than with a single knife blade is the preservation of the straight edge of the blade.
Traditional household scissors do not need to be disassembled
In days gone by, scissors sharpeners pulled across the land and offered sharpening on the front door with their mobile grindstone. For this, they usually opened the scissors and sanded the two blade cutters on the rotating whetstone. Only with experience and skill could they achieve a good result.
Today, most household scissors can be sharpened without a rotating grindstone. Conventional kitchen and nail scissors can be easily sharpened again with several aids.
Aid for sharpening by cutting is particularly well-suited:
Sandpaper (120 to 400 grit)
- Alupa paper
- The scissors must make a variety of cuts through the paper. As a guideline twenty slits of at least twenty centimeters in length can be used.
When sharpening with sandpaper, the grit side should be flipped after each cut to reach both blades. Overall, forty cuts are usually sufficient.
After sharpening, the resulting sanding dust can be removed with a moistened paper towel or better, with a leather cloth. The leather has the advantage of removing any burrs from the blades.
Special scissor types
There are some special scissors, for which a more precise sharpening after disassembly of the wings is recommended. These include tailor's scissors, barber scissors and hedge trimmers. A required razor sharpness can not be achieved without dismantling.
After loosening the retaining screw, the individual blades are only sanded from the outside with beveled chamfer according to their cut. Suitable grinding stones are hydrated combination stones with two grain sides. The coarser grain should be 120 to 220. For fine sanding, a grain size of 300 to 400 is recommended. Subsequent removal of the burrs with a blade leather is required.
In order to recognize the correct angle and the areas already covered when sharpening, coloring the bevel with a felt-tip pen is helpful. In this way it can be tracked exactly where the cut has already been made and which areas have not been reached so far.
Table-top machines and home remedies
There are many grinders on the market, especially on the Internet, which are intended to simply pull the scissor blades for sharpening. These machines are similar in function to a whetstone made of metal. Most of them have metallic grinding wheels inside, over which blades are pulled.
The result of these machines is worse than cutting through abrasive or aluminum paper. In addition, often an imprecise angle guide and a rather rough impact on the blades are added. This can lead to unschedeability after a few sanding cycles and severely affect the cutting result of the shears as a whole.
Also less recommendable are "home remedies" such as canning jars or pins. Apart from the effort, the results in no case exceed the simple cutting results.
A grooved wheel is required for gears
If the blade to be sharpened has teeth on one side of the blade, it can also be sharpened to some degree by sharpening. When disassembled, a special rotating gear grinding wheel is required. It consists of a grooved surface adapted to the size of the teeth.
Tips & Tricks Always use your scissors exclusively for special cutting material. Cut only cloth with a pair of scissors, only a piece of paper and cardboard with a pair of office scissors and no metals with a utility scissors in the kitchen. This also includes metal fiber reinforced straps, which are sometimes used on new products as a holder for type and price tags. Also electrical cables should be taboo.