All comments are now on the Fireball forum, a place to ask questions, share your thoughts, and easily search for topics that interest you. Find it here: https://fireball.discourse.group/ I put files to the test to see if back-dragging dulls a file like many claim. I test coarse, medium, and fine files after I built a large testing rig to stroke tens of thousands of times. I also test if back-dragging unclogs files. I use the slow-motion camera to analyze the results and use a microscope to observe all the files! Get the Pferd Files Here! null Our New Hardtail Vise null The Gloves I Wore null How did I build this Machine? https://www.youtube.com/watch?v=52d0TmmQ5yI Musicbed SyncID: MB01UXDSPZMMX9Q