If you enjoyed this article, I’d like to ask for your support. Scientific American has served as an advocate for science and industry for 180 years, and right now may be the most critical moment in ...

Twist drills do not make accurately sized or good finish holes; a reamer of some type is often used to cut the final size and finish. A reamer will not make the original hole; it will only enlarge a ...

Tapping screws form mating threads in materials they are driven into. There are two basic types: thread forming and thread cutting. The thread-forming screw displaced material around the pilot hole so ...