What are the reasons for single-sided burrs in metal stamping parts?

Mold assembly errors. For example, if the punch and the fixed plate are not perpendicular or are loose due to wear, or the positioning pins are loose, the correct fixed position of the male and female molds cannot be guaranteed.
Guidance accuracy is poor. The excessive matching clearance of the mold guide parts causes the center lines of the upper and lower molds to not coincide, affecting the uniformity of the stamping gap.
Installation error. When installing the non-guided mold, the upper and lower mold positions are incorrect, resulting in uneven gaps. If the surface of the upper mold plate or bottom plate is not clean, or the upper mold screws are improperly tightened, the working part will tilt.
The mold deforms during operation. For example, if the leakage hole of the punching mattress plate is too large, the lower template of the mold is too thin, the rigidity of the die is not enough, etc., the gap will be affected by the deformation of the mold during stamping.
The gap between the punch guide rails is too large, the parallelism between the bottom surface of the slider and the work surface is not good, or the sliding direction of the slide block is not perpendicular to the work surface.
When the maximum resistance when stamping the workpiece exceeds 80% of the nominal pressure of the punch machine, the “C” shaped bed of the open punch machine will easily deform, causing the center lines of the upper and lower molds to not coincide.
The flatness of the sheet is poor, causing the punch with a smaller diameter to tilt during the metal stamping process.
Due to improper mold material selection, forging and heat treatment processes, the die is deformed during heat treatment or wire EDM, affecting the uniformity of the die gap.