The pitch diameter Dpw is usually equal to the nominal diameter of the ball screw.

Stroke of lead Ph ball nut when it rotates 2π radians relative to ball screw.

Nominal lead Ph0 is usually used as the lead value of dimension identification.

When the ball screw or ball nut rotates, the axial displacement of the ball screw or ball nut.

The effective stroke Lu specifies the stroke part required by accuracy, that is, the length of the ball nut body on the stroke.

In addition, there are thread outer diameter d 1, thread bottom diameter D2, nut outer diameter d, nut bottom diameter d2, nut thread inner diameter D3, ball diameter Dw, thread total length L 1 and so on.

Go to the library to find some reference books. I hope it helps you!