When using this type I drill a small hole first to keep cutter from walking off spot weld .Here is a link to one so you can see what it looks like.
spot weld drill
When using this type I drill a small hole first to keep cutter from walking off spot weld .
Yep.....1/8 inch center drill, with this you work on the waste panel side. It leaves a small hole in the save part. Drill tell you see the dark ring showing up.
The outside is 3/8. You can buy replacement center drill's, and can sharpen the cutter.