Grinding the die
As soon as the die is milled the rough edges and burrs need to be removed. A job that sounds simple however it needs to be done with great precision.
As soon as the rough shape is done the die is prepared for heat treatment. After machining burrs and rough areas need to be smoothened. This needs to be done before heat treatment because afterwards it will be very labor intensive.
During this phase the die is checked for flaws and mistakes. Corrections can still be done due to the soft condition the die is in. The grinding is hard work and requires a lot of knowledge and patience. Even though it looks like a relative simple operation it needs to be done with a lot of precision. Every bit of material that is removed could make a difference in the flow of material in the tool.