How Is A Die Made?

How is a die made?
What is a Hub?
A couple of questions you might have asked yourself during the discussions found on the Coin Community Forum. The dies are made from stock bars that are shaped to make dies and imprinted/pressed into shape with a hub To understand the process you might want to look at my chart of the progression of the die making process. We will mainly be covering the last two steps. "Working hubs" and "Working dies."

The earlier steps of preparation of the hubs and dies help us to realize that there is a positive and a negative of the steps. The coins being a positive, the dies being a negative and hubs being a positive. So what does that mean? A positive shows the devices as we normally see them. A negative is the die that during the strike makes a positive coin. The hub is a positive making the die as negative to strike a positive coin. Sounds complex, but seeing this in an image will help us see what I'm talking about.
So lets start with the stock material and the dies:

In this image we see the process of stock, hubs, die and hardening to temper the dies.
Note on the left the stock material which is cut into lengths and setup for making the dies:

These images were from an online site showing the a little background of the San Francisco Mint. So we will be seeing mostly proof dies.
Here is the 2014 Kennedy half dollar. This is the Hubs for the Proof halves:


Note the design is a positive. Note on the obverse hub, the 6 lines around the design? These are called lugs and grooves to keep the hub and the die in place to keep from making a doubled impression on the dies. This is transferred to the dies and removed from the dies in a later process.