We've already talked about threads, and you probably knew what a thread was even before we brought it up. However, in the manufacturing world, we use several words to talk about threads that you may not have heard before.

Die: A die is a tool used for adding a thread to the outside surface of a cylinder, like on a bolt.

die bolt

Tap: A tap is a tool used for adding a thread to the inside of a cylindrical hole, like on a nut.

tap nuts

Tapped: If something is tapped (usually a hole) it means it has had a thread added to it. Often, instead of saying that a hole is threaded, people will refer to it as "a tapped hole". As you may have guessed, this is because a "tap" is used to make the threads.

Taps and dies are measured using the same thread callout standards we discussed on the thread page, so a 1/4"-20 tap would be made to use a hole that a 1/4-20 bolt would fit into.

In the next couple labs, you will get to practice using a tap and a die.