Gun Drill Sizing and Selection: How to Choose the Right Drill for the Job
I have a process I use for every new gun drilling job. It starts with the bore print and works through diameter, shank, length, tip geometry, and coating in that order. Skip any of these steps and you risk a tool that wanders, breaks, or wears out before it reaches depth. Here is my full sizing and selection process, along with the reference tables I keep pinned above my bench. ...