Trapezoidal Thread (Standard) DIN 103
This thread is the metric ISO trapezoidal thread. There is also a corresponding fine thread variant for this thread type. Trapezoidal threads are mostly used as motion threads. Their profile is shaped like an isosceles trapezoid, and the thread flanks are broad with a flat base. Due to their special geometry, trapezoidal threads can transmit forces and movements, and are therefore often used in lead screws, e.g., of lathes or spindle presses.
The metric DIN 103 trapezoidal thread has a flank angle of 30°. All dimensions and the pitch are given in mm.
The thread designation of the DIN 103 trapezoidal thread consists of the abbreviation Tr, the nominal diameter, and the pitch. A thread Tr 18 x 4 is a trapezoidal thread with an 18 mm nominal diameter and 4 mm pitch.
The table below lists only the dimensions for the standard DIN 103 trapezoidal thread. The corresponding fine thread can be found on a separate page. Occasionally, both thread types are combined in one table. Alongside the thread designation, the external diameter and core hole diameter for the DIN 103 trapezoidal thread are also listed. We carry dies and taps for the trapezoidal thread in various designs. Simply follow the links in the table to find the desired size.