An electric impact tool for fastening screws or bolts, which prevents a motor drive from being stopped before a screw or bolt is fully tightened. At least when the torque change ratio is substantially zero and the reference index is or is greater than the fault determination threshold, the fastening determiner determines that the fastening operation is completed. The reference index is the impact number of the hammer when the torque variation ratio is positive, and the fault determination threshold is calculated by using the maximum value of the torque variation ratio in the case. Because the number of hammer impact caused by fault in fastening in the manipulation of less than due to the screw or bolt is fastened completely by hammer impact times, so it can be produced by the former case the torque increase generated and the latter case the torque increased to distinguish.
Add: TANGHUI INDUSTRIAL PARK, JIAXING ECONOMIC DEVELOPMENT AREA, JIAXING, ZHEJIANG, CHINA
Contact person: Ms. Nancy Yue