Stepped Washers for Supercharger

I took some 1.25" round aluminum stock and turned it in the lathe to make sure it was perfectly round.  While in the lathe I drilled a hole through the center and tapped it 5/16-24.  I then cut it to have a washer blank that was about 1" thick.

I then mounted the washer in a 1-2-3 block with a bolt from below, making sure the bolt did not protrude more than a 1/4" into the washer.

I mounted the 1-2-3 block in the vise and used a set of parallels to make sure the block was elevated high enough to clear the jaws of the vice.

I milled the step into the washer at a depth of 0.145".  I used multiple passes to avoid choking the cutter.

The washer has the correct step design and cut depth, but the over-all washer thickness is way too much.  We need to cut it down to a more reasonable size - over to the band saw we go.

Now that the washer is the right htickness we can chuck it back up in the lathe and clean it up.  I put a slight chamfer on the outside edge and ran down the sides to clean up all any marks left.

The final product.