Tempering is done by heating to a dull, plum red. This is very difficult to see and the use of heat indicating Tempil stick crayons can be a good aid. This operation must be performed in the dark. The dies were placed in a cooling forge and pulled out every minute so that the progress could be monitored. The plum colour can only be seen when the die is placed in a very, very dark place.
A guide was constructed to to maintain alignment of the top and bottom die, this also serves a secondary purpose in holding the dies apart when not in use.
Below we see the die in the raised position.
And below in the closed position. A simple tap with the hammer will cause the dies to close on to the work piece.
Here's a piece of 1.5" (40mm) EN9 (1055) that I spent a few minutes working on.
This device makes reducing the stock easier as it provides a fixed target. With the conventional hammer and anvil method you end up chasing the stock around the anvil no matter how hard you try to keep it still. This device forces the stock to stay in the right place and provides an immovable, fixed target that you can really swing your hammer at. One slight dissadvantage is that as the dies are in constant contact, they will draw heat from the stock until they warm up. This could be rectified by adding a spring that lifted the dies apart between strikes. Tomorrow I'll fabricate a device that locks the stock firmly in place allowing a single operator to use a sledge hammer.