The "Screw" tool starts a repetitive "Spin" combined with a translation generating a screw-like, or spiral-shaped, object. You can use this to create screws, springs or shell-shaped structures.

Figure 45. How to make a spring: before (left) and after (right) the Screw tool.

The method for using the "Screw" function is strict:

If there are multiple 3DWindows, the mouse cursor changes to a question mark. Click on the 3DWindow in which the "Screw" is to be executed.

If the two "free" ends are aligned vertically the result is the one seen above. If they are not, then the translation vector stays vertical, equal to the vertical component of the vector joining the two 'free' vertices, while the horizontal component generates an enlargement (or reduction) of the screw as shown in Figure 46.

Figure 46. Enlarging screw (right) obtained with the profile on the left.