Cutting thickness
The cut thickness of scissors is the largest thickness of metal that they can handle normally.
This parameter is directly related to the type of instrument (see the relevant paragraph). So, manual shears for sheet metal mainly have a cut thickness of up to 1.5 mm (with some exceptions), and in powerful
lever models and bolt cutters this figure can exceed 15 mm. When choosing, note that, other things being equal, a large cut thickness means a larger, heavier and more expensive tool. So it’s worth choosing with some margin, in case of unforeseen situations, but this margin should not be too large.
Also note that in the basic characteristics, the cut thickness is usually indicated for a certain type of metal, and when working with other materials, it may be less than the claimed value. These nuances must be specified according to the instructions and other detailed information of the manufacturer.
Steel grade
The grade of steel from which the scissors are made — or at least their cutting part (in some models, the material of the handles may differ from the material of the knives).
This parameter is most often indicated by the type of steel or by the main alloying components included in its composition. For example, the designation CS stands for "carbon" and refers, usually, to traditional unalloyed tool steel. Such steel is prone to corrosion under the influence of moisture, including atmospheric, so it is advisable to periodically lubricate such a tool and keep it in a place with low air humidity. Markings Cr-V and Cr-Mo denote steel with chromium-vanadium and chromium-molybdenum alloying additives, respectively. Both of these varieties are highly resistant to corrosion, while the addition of molybdenum allows you to also reduce weight without sacrificing strength. There is also a tool made of stainless steel marked SS; such an alloy contains only chromium as an alloying additive. Other types of steels are rarely used in metal shears; a description of such materials, if necessary, can be found in special sources.
Length
The total length of the tool.
This parameter is specified for manual sheet metal shears (see "Type") and tools of a similar design. In addition to dimensions, it determines another important point — the working force. The greater the length of the scissors, other things being equal, the greater the length of the lever that the user acts on, and the greater the force transmitted to the jaws with the same pressing force. Accordingly, tools for working with thick and hard materials inevitably turn out to be long (for example, the length of a bolt cutter can exceed 1 m). And short handles make the scissors easy to store and transport, but require more effort when working.