Lead screw diameter 8mm, length 500mm Copper nut, with 4 holes for fixing to the machine Thread: thread Screw pitch: 2mm; Lead: 8mm If you want higher accuracy, it is recommended to use the anti backlash copper nut Size:T8x8 The lead of the thread is 8mm, which means that the nut move 8mm if the nut turns one circle. The advantages of the leadscrew are: Large load carrying capability Compact Large mechanical advantage Precise and accurate linear motion Smooth, quiet, and low maintenance, very suitable for 3D printer z . Minimal number of parts So this lead screw is very suitable for 3D printer Z , such as and Prusa i3. The screw type of this lead screw is thread. Threads are generally stronger than square threads due to their trapezoidal thread profile, which provides greater load-bearing capabilities. colour:Silver + gold Material:stainless steel Package Contents: 1 * 500mm lead screw 1 * copper nut Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.