To Define a Pin Constraint
1. Click > 
Pin. The Pin Constraint dialog box opens. This dialog box allows you to control the translation or rotation about the axis of a cylindrical surface in 3D models.
Pin. The Pin Constraint dialog box opens. This dialog box allows you to control the translation or rotation about the axis of a cylindrical surface in 3D models.2. Specify a Name for the constraint or accept the default name. Click the color swatch adjacent to Name if you want to change the color of the icon, the distribution and the text displayed for the pin constraint.
3. To create a new constraint set, select a constraint set from the Member of Set list, or click New to open the Constraint Sets dialog box.
4. Select the cylindrical surface(s) to constrain. You can select the geometry before or after you open the Pin Constraint dialog box. The References collector displays the selected surfaces.
5. Select the required combination of angular and axial constraints under Properties. Use the table below as a guideline.
Angular Constraint  | Axial Constraint  | Pin Constraint |
|---|---|---|
 | | Allows rotational and axial displacement but constrains radial displacement. |
|  | Allows angular displacement but constrains radial and axial displacement. |
| | Allows axial displacement but constrains radial and angular displacement. |
| | Constrains radial, angular, and axial displacement. |
6. Click OK.