FIELD: metallurgy. SUBSTANCE: stool has central depression in its upper part made in the form of overturned truncated pyramid with rectangular bases and depth equal to 5.0 - 25.0 % of stool height and length of no more than 90 % of its total length. In the case side walls of depression belonging to wide planes have step, space to which from stool top is 5.0 - 15.0 5 of stool height. EFFECT: improved design. 3 dwg
