... Twist drill, throng drill, thin wall drill, anomalous drill, and so on. 3.CE universal drill grinder MR-21A This drill ... watch the operation videoTechnical parameters:Range of drill diameter: 3-21mmGrinding wheel diameter: 125mmVoltage: 220VMotor power: ... steel of twist drill, ladder drill, throng drill, thin wall drill, percussion drilling, anomalous drill, etc. Universal Drill Grinder ( 3~21mm ) MR ...