Peter, Positive rake on tools used with brass will cause the tools to "dig or hog in" and damage the work. For the same reason, I keep a set of drills that have had their rake removed and are used only on brass/bronze. Jesse Livingston in summat cooler W. Tennessee MODEL ENGINEERING DISCUSSION LIST. To UNSUBSCRIBE from this list, send a blank email to, modeleng-request@xxxxxxxxxxxxx with the word "unsubscribe" in the subject line.