Mechanical power press works on the principle of slider crank mechanism or modified mechanisms such as Kuncle joint or linkage drive. The tonnage of the press (pressing force) is required before the slide reaches the bottom dead center (BDC). The reason is that the metal sheet has some thickness and forming force should be transferred on the sheet. So, the Rated Distance is the distance from the BDC (bottom dead center) at which full force (theoretically) or tonnage of the press is achieved.
The Rated Distance and Stroke of the press are generally provided by the Press User or the Client. Then the press manufacturer designs the Slider Crank system based on the inputs provided by the client.
Refer to the calculation program to simulate the tonnage of the press, rated distance, crack radius or eccentricity, and connecting rod length.