The methode is the same a engineering a (metric) bolt.
If you look into the design tree you will see how its done....
keywords: Helix, Swept cut,
Hans is right, but you repeat the helix depending on the number of starts required. Have included a sample file in solidworks 2013.
Attachments4_Start_Helix.SLDPRT, 474 KB
Look at my model: Worm Wheel.
This model is packed with : Helix, Swept boss base, Swept cuts, circulair patterns, metric thread etc.
If you download this model you can use it as a guide.
Hope this will help you to make the model you want.