Eshboboev Sardor Nurbobo ugli, Rakhmatov Sirozhiddin Eshmakhmadovich and Nuraliev Novruz Shoymardon ugli 2021. INVESTIGATION OF THE MICROSTRUCTURE AND HARDNESS OF 20GL STEEL SAMPLES CUT FROM A WEDGE-SHAPED AND A SIDE FRAME AFTER VOLUME-SURFACE QUENCHING. European Scholar Journal. 2, 5 (May 2021), 302-309.