Screwdrivers don't have a round head, because a round head has no torque at all. The word is to guarantee torque, and the cross allows the force to be distributed more evenly. According to the power source, there are manual screwdrivers and electric screwdrivers; according to the batch head or the cutter head, there are a flat head and a cross (phillips).
Yuqori sifatli tornavidaning boshi{0}}nisbatan yuqori qattiqlikka ega buloqli po'latdan yasalgan. Yaxshi tornavida qattiq, lekin mo'rt emas, qattiq va qattiq bo'lishi kerak. Vint boshining ochilishi kal va sirpanchiq bo'lganda, vintni bolg'a bilan urib, vintning yivini chuqurroq qilish mumkin, shunda vintni osongina burab qo'yish mumkin. Egilmasin. Umuman olganda, tornavida boshining qattiqligi HRC60 dan kattaroq va zanglash oson emas deb umid qilinadi.
