edm slotComparison of fatue cracks and EDM slot shapes and widths. The upper and middle schematics show the cracks EDM slots in the hole bore crossEDM Slot Sizing Block. This block contains nine EDM slots from 0.100 to 0.900 deep. Slot width is 0.011. Nominal depth is laser engraved on the side of the block. In accordance with PH Dwg.