The invention discloses a variable-speed circumferential low-stress 
bending fatigue crack precise blanking 
machine and a blanking method of the variable-speed circumferential low-stress 
bending fatigue crack precise blanking 
machine. The variable-speed circumferential low-stress 
bending fatigue crack precise blanking 
machine comprises a variable-frequency motor, a large belt 
pulley, a V-shaped belt, a small belt 
pulley, a two-stage gear accelerator, a high-speed main shaft, a sliding rail supporting seat, a screw compression spring, a columnar hammer head, a feeding sleeve, a ball guide 
bushing, 
metal bars, a clamping hand, a clamping cylinder, a feeding cylinder, a hydraulic clamping feeding mechanism support, a machine body, a seat plate, a 
servo motor, a speed 
reducer, a coupler, a 
ball screw supporting seat, a screw, a nut, a 
ball screw, a deep groove 
ball bearing and a key. The variable-speed circumferential low-stress bending fatigue crack precise blanking machine is high in geometric precision of blanking workbanks, free of corner collapse and 
radial deformation, perpendicular and smooth in fracture section, few in burrs, and high in use ratio of material. The 
stress concentration effect, the 
resonance effect and the bending fatigue of an annular V-shaped groove are utilized to enable the critical value of the 
impact speed of vibration on the 
metal bars to be lower than the critical value of the speed in the high-speed shearing process, and the blanking machine is applicable to precise blanking of the 
metal bars of different materials.