Fine blanking and parameters of surface quality in fine blanking

FINE BLANKING and PARAMETERS of SURFACE QUALITY in FINE BLANKINGCem ALAYBEYO LUABSTRACTFine blanking is an advanced and precision stamping process, in which a component withprecision geometries and smooth cut surfaces can be produced without any further majorsecondary operations.The clearance values between die and punch should also be less than those in conventionalblanking processes. This is the main reason for obtaining smooth and precision surfaces.As a result, precision and productivity are increased and manufacturing time, cost andmaterial waste are decreased significantly by preferring fine blanking as a cutting method.Furthermore, usage of vee-ring and counter forces is essential in fine blanking, while they donot exist in conventional methods. In fine blanking processes, therefore, all of the materialthrough sheet thickness can be sheared between punch and die surfaces without any fracture;whereas, its range is almost 1/3 of the thickness in conventional processes.There are o number of parameters influencing the precision and surface quality obtained infine blanking processes, which are structure of sheet metals, thickness of sheet used, tensilestrength of sheet material, dimensions and surface condition in tooling, cutting fluids andoperation an die temperatures.This study explains fine blanking technology, tools and presses, fine blanking materials,forces and parameters.Keywords: Fine blanking, microstructure, vee-ring force, counterholder force, dietemperature, conventional stamping