[SCadaddle]

You cut a "clean out bolt" or a "thread chasing bolt" with a 3 corner (or triangular) hand file. Run the file parallel to the bolt to cut out a "V" shaped "notch" for the trash to occupy. When you look down at the end of the bolt with the head of the bolt in your fingers, the end should look like a pizza with a missing slice but tapering to a whole pizza pie several threads down towards the head of the bolt. That's the best I can explain it.