Circular wear marks on the bottom of drill bits are a key indication of the drill bit slipping inside the drill chuck. The main reason for this problem is cutting fluid or lubricants used come in contact with the chuck, when this happens tightening the chuck will only go so far. When this happens the bit stops cutting the metal and starts spinning within the drill itself. if this happens often the drill bits strength is reduced and could cause it to prematurely break. In some cases this can be very dangerous because the bit may become lodged in the metal, if this happens and the chuck regains grip on the bit the metal you are drilling could be sent spinning or the drill could be ripped from your hands.
Keeping your drill chuck clean is the best way to ensure you will never have problems with your bits slipping. This is a very simple process and will only take a couple minutes.
First adjust your chuck so it is about half way open so the jaws are exposed but there still some room between them.
Spray the edge of a rag with PRE Painting Prep and go over each of the jaws to remove any dirt, grease or lubricants that may be on them. If you have cotton swabs they also work great. Spray pre on the end of a swab to clean each of the jaws.
Do not spray the chuck directly because it may remove the bearing grease further inside the chuck, causing it to lock up.
Check out the Eastwood Blog and Tech Archive for more How-To’s, Tips and Tricks to help you with all your automotive projects. If you have a recommendation for future articles or have a project you want explained don’t hesitate to leave a comment.
– James R/EW