How to add a grove (or slot) into a disc?

I have created a cylinder, flattened it into a disc, and now I would like to add a slot to this disc. I plan to add many slots, eac aligned from the center to the disc edge. How can this be done?

Thanks!
Dan

In F5, Material Buttons (Red ball), MapTo tab, to the right of ‘Col’ is ‘NoR’ for Normal Mapping. It’s not true normal mapping but Bump Mapping, but you can make an image of a Black dicsc with a White ring and add it as a Texture. Turn off Col and turn on Nor, then adjust the value in the Nor slider below. When you render it will bump the White ring out (or in if you you hit the Nor button twice to its yellow state).

%<

This is the way I did it. Create cylinder with as many sides as you need grooves, I did twelve. Switch to vertice mode and sellect all. Use the bevel script in the Scripts sub menu found in the Mesh menu. Knowing how much bevel to set is difficult so you may want to save beforehand in case you need to try again. Un- sellect all then sellect all the vertices on one end of cylinder and Scale 0% on the appropriate axis to get a nice flat face again, repeat for other end. Sellect the faces that form the wedge shapes between the grooves and extrude.