The pins are sub-assemblies of 3-cone drilling bits used to dislodge the rock. Pin head may have different shapes (chisel, hemisphere, etc.) according to the intended nature of the rock. The pin body has a cylindrical shape and serves to hold (embed) them into the body rolls. The pins are made by sintered carbide that combines the best contradictory properties such as hardness and toughness. Because the sintered metal carbides break after suffering a very small plastic strain, they are classified as brittle materials. In the following, the authors present results of studies conducted under conditions that partially reproduce the actual conditions (lack of drilling fluid, however, acutes test conditions), on the cutting structures of the 3-cone drill bits for making it clear that in these subsets, the tensions while working at the base of the drilling hole do not exceed the strength of materials they are made of.