Transmission galaw na matu screw lang ai lam gaw labau kadun ai. Htunghking screw ni gaw galoi mung n kaja ai shara hte n-gun kya ai lam ni a majaw hkra machyi hkrum nga ai. 1898 ning hta she masha ni gaw ndai lam ni hpe gram lajang na matu shawng nnan shakut wa ai shaloi, nut hte screw lapran hta n-gang ball ni hpe bang nna, sliding friction hpe rolling friction hte galai kau ai. 1940 ning hta, ball screw ni hpe mawdaw steering system ni hta bang nna, shanhte a jai lang ai lam hta rawt malan lam kaba byin wa nna, htunghking ACME screw hpe kalang ta galai kau ya ai. Kade nna ai aten hta, ball screw ni gaw, hpaga lam hta grau nna jai lang ai arung arai langai byin wa sai.
