The Altman Gang Die is based on the principle of shearing rubber: that is as follows:

When rubber is confined in an area it will flow in the direction of least resistance. As the area is limited further the flow will increase until the elastic limits of the material is reached. For a male and a female die to generate this type of compressive force in a piece of rubber, the punch must pass as close to the die as possible with little or no contact. From this it is possible to conclude that a very soft stock will punch out only if the clearances are near metal to metal. but a hard stock will allow for greater clearances. In the Altman gang die a maximum total clearance of less than Five-Ten Thousands of and inch is utilized so that even soft material will punch. This is maintained even though material may vary in thickness and hardness. Our dies utilize the finest tool steels and are hardened and ground to assure maximum life and precision fit. All cutting die parts top and bottom are hardened to 60 Rockwell assuring that the tool will maintain a sharp edge.
The Altman Gang Die falls into four categories

1. Gang Trim Die, or O.D. only Trim Die
2. I.D., O.D. Progressive Die
3. I.D., Slit, O.D. Progressive Die
4. I.D. and O.D. Compound Die