# Tutorial - Modeling Unified screw threads on bolt in SolidWorks?

Here is the tutorial.

1. ### Step 1:

Start SolidWorks in part mode.

2. ### Step 2:

Top plane>>Sketch.

3. ### Step 3:

Draw a circle of 20mm dia.

4. ### Step 4:

Extrude it by 50mm.

5. ### Step 5:

Top face>>Sketch.

6. ### Step 6:

Draw a polygon inside a circle of 32.5mm dia.

7. ### Step 7:

Extrude it by 10mm.

8. ### Step 8:

Top face>>sketch.

9. ### Step 9:

Draw a circle tangent to sides of polygon.

10. ### Step 10:

Extruded cut.

11. ### Step 11:

Check flip side to cut. Draft enable at 45.00º.

Chamfer.

13. ### Step 13:

At distance of 3mm & angle 45º.

14. ### Step 14:

Top plane>>sketch.

15. ### Step 15:

Select the outer edge and then convert entities.

16. ### Step 16:

Curves>>Helix and spiral.

17. ### Step 17:

Defined by Pitch and revolution. Pitch=3mm and revolution = 15.

18. ### Step 18:

Right plane>>sketch.

19. ### Step 19:

Draw a profile like this. Since pitch is 3mm so keep the length be little less than pitch since at 3mm it will have intersection error.

Sweep cut.

21. ### Step 21:

Select the profile and the helix as the path.

22. ### Step 22:

And we have the unified screw threads.