Proposal of implementation of unequivocal marks for tangential-and-rotational bits of cutting worm drums  
Krauze K.

S u m m a r y
Use of different types of roadheader bits, especially tangential-and-rotational bits of cutting worm units, should provide minimal resistance of mining process, and the best possible durability of cutting tools, cutting drums and mining machine. The most important problem in this case is a such position of cutting bits which enables suitable operational cutting angles. Analytical method for determination of operational cutting angles, developed for analytical purposes, requires a knowledge of design parameters of bit, holder and cutting drum. Unfortunately, there is a lack of such data in catalogues of companies which manufacture cutting tools and holders what makes calculations difficult. That is why implementation of permanent marking of selected design parameters, in order to make a selection of cutting bit or holder easier, is suggested.