Trapezoidal lead screws and nuts are power transmission screw threads similar to the Acme series but made to metric dimensions and standards. One such standard is the German Metrisches ISO-Trapezgewinde DIN 103 which has been adopted by the International Organization for Standards (ISO). Sometimes misnamed "metric Acme" or "metric M series Acme" Trapezoidal lead screws look like Acme screws and have the same stout thread form and the same robust and durable features as the Acme series.