The 1 blanking punching (trimming)
Defect: burr is too big, deformation, scratches on the surface, size does not match, small hole.
(1) large burr, the die gap is too large or too small; edge wear; guidance precision; the convex and concave die position misalignment
(2) deformation and hole spacing is too small; the pressure plate and the concave model fit is not good; the gap is too large.
(3) surface scratch, operating out of Ball Bearing 15012 drag, pull phenomenon; sheet in the cutting process the scratch etc.
(4) size does not match, feeding is not in place; the positioning device is damaged or loose, position movement etc.
(5) small holes, punch punch length is not broken;

2 drawing
Defect: cracking, wrinkling, surface strain, wave, drum kits, pits, pits and other.
(1) crack, punch R corner radius is too small; the edge pressing force is too large; material property or material size is too large; clearance between punch and die is too small; improper lubrication; positioning inaccurate; punch R angle or drawbead is not smooth, rough and so
(2) the wrinkling, punch R corner radius is too large; the edge pressing force is too small; material size too small; clearance between punch and die too big too much; lubrication; positioning inaccurate; drawbead layout side, the height is not enough.
(3) surface strain, the working surface of Ball Bearing 15012 the die has a scar; surface defect; impurities, such as waste lubricating oil
(4) the wave, drum kits, pits, pits, blank holder force; improper lubrication, die cavity surface dirty dirty; materials; ventilation hole plug; mold surface uneven, dirty lubrication oil etc.
3 flanging
Defect: flanging is not vertical, the flanging height inconsistencies, flanging galling, flanging crack etc..
(1) is not vertical, flanging die clearance is too large
(2) the flanging height inconsistencies, clearance between punch and die is not uniform; positioning inaccurate; blank dimensions are not allowed
(3) has a scar flanging galling, cutting edge; surface impurities; edge hardness is too low
(4) the flanging crack, burr trimming; clearance between punch and die is too small; flange shape mutation