However, when the part design involves irregular outer contours or large holes requiring a long cycle time, then dedicated tooling can be justified for smaller production runs. Certain parts with tightly spaced hole patterns or slots require expensive dedicated tooling, however with the CNC turret press, these parts can be easily made using standard tooling. To maximize utilization of material , parts are nested as close to each other as possible. After punching, the parts are separated by vibrating them in a shaker. This is very cost effective since no special tooling is necessary for separating them.
Burrs are inevitable in the stamping process.
The burrs are formed on the side of the sheet metal where the punch exits. When designing parts, the burrs should be confined to areas that will not be exposed to handling and should be either folded away or otherwise shielded form the user. Otherwise, an added operation of deburring needs to be done at added cost. This releases the residual stresses in the material, which causes bowing or twisting of the part. Proper use of clamping and strippers can minimize this, as can subsequent straightening operations.