Eshboboev Sardor Nurbobo ugli; Rakhmatov Sirozhiddin Eshmakhmadovich; Nuraliev Novruz Shoymardon ugli. INVESTIGATION OF THE MICROSTRUCTURE AND HARDNESS OF 20GL STEEL SAMPLES CUT FROM A WEDGE-SHAPED AND A SIDE FRAME AFTER VOLUME-SURFACE QUENCHING. Euro. Sch. J. 2021, 2, 302-309.