Something Jim Rozen posted prompted me to post this. He uses a ball end mill in the lathe tool post to cut thread reliefs. Well, router bits can also be used for this. Carbide router bits are now fairly inexpensive and come in a huge variety of shapes. So both convex and concave radii can be cut along with many other contours. Since these tools are made for wood they seem to leave a worse finish that cutters made for metal. But the carbide router bits will even cut stainless steel. So for the home shop, where money is often less plentiful than time, the extra time it takes to sand the part to a better finish is OK. Even though 1/4" shanks will work, the 1/2" shanks are really much better. Good luck! Eric R Snow, E T Precision Machine
- posted
18 years ago