Thinning the ends of tubes, engine bells, etc.

[Andrew Gorman]

For years I've used various sizes of countersinks to thin round open ended parts, especially engine bells. For a current project I needed to thin the open end of a thick plastic tube. I only have a 90 degree countersink in that size, and the end still looked too thick. So I broke out the step bit set I picked up at Harbor Freight a while ago and it worked great! Thinned the outside walls far enough back to look good, and then angled back to the original ID. I just spun the bit by hand. Here's a link to the tool, but since it is Harbor Freight pay no attention to the list price. They are always on sale.
http://www.harborfreight.com/3-piece-ti ... 91616.html