Manual screw jack is well known as a hand wheel screw jack, a hand crank screw jack, or a hand operated screw jack, that is driven by a hand wheel or crank or handle. The best advantage is suitable for heavy load, low speed, low service frequency. Jacton manual screw jacks have different configuration form and assembly type,and the lifting height can highly customized according to users’ demand, low cost and easy operation. Self locking ACME screw jack are recommended for manually operated jacks.