How to drawing a screw?

Hello,
I need some help from anyone over here who can teach me how to draw a screw instead of using the one in the catalog. Or Else can someone tell me how to make a shaft to be threaded.
Thanks.

You have to draw a helix in wireframe workbench and later draw a section (regard to screw form) and then rib the section through the helix and substrate from primitive cylinder.

[Mech]

I used the slot command from the part design workbench..
Modeled the screw with part design, went to gen shape and created some points, a line to define the centerline axis, the helix with the lead of the thread pitch, and a plane on that helix.
Then back to part design and sketched the thread profile on the plane I created on the helix, and used the slot command to cut the threads.

[MrCATIA]

Be careful when modeling screw threads. Besides wasting alot of your time, they can eat up alot of file space and graphic memory and really impact your performance.

If you need to model a thread, then either a rib or slot can be used to sweep the thread profile through a helix curve.

A much better way to define standard screw threads is to use the Thread/Tap tool in Part Design. It's the icon right below Thickness. This Thread/Tap tool identifies threaded features, although it does NOT show the thread on the 3D model (to show what's threaded. you might want to change the color of threaded faces). When you make a drawing from you 3D part, threads will be drawn based on the features.