The contribution is devoted to geometrical questions related to the issue of adjusting the active parts of the cutting tool. There are three modifications of the cutters: With the blade beveled inward and bevelled outward, the blades formed by the intersection of two cylinders. The necessary schemes of these solutions and the necessary mathematical relations are published.
The paper describes the issue of wear of shears in shearing tools. It is pointed out to theoretical knowledge from the issue and also in experimental, or the practical part contains specific knowledge about the wear of the active surfaces of shearers.
