The trapezoidal metric thread form is similar to the Acme thread form, except the thread angle is 30°.It is codified by DIN 103. While metric screw threads are more prevalent worldwide than imperial threads for triangular thread forms, the imperially sized Acme threads predominate in the trapezoidal thread form.
The advantages of a leadscrew are:
Large load carrying capability
Compact
Simple to design
Easy to manufacture; no specialized machinery is required
Large mechanical advantage
Precise and accurate linear motion
Smooth, quiet, and low maintenance
Minimal number of parts
Most are self-locking











