Intelligent Assembly Solutions

Electric System Wrenches - Tool Selection


The YOKOTA electric system wrenches with integrated torque transducer and angle sensor offer a large reduction of energy consumption, a high degree of accuracy and fantastic work efficiency.

Electric drive:

  • Reduction of energy consumption – Lean and Green.
  • No need for pneumatic installation with compressor, air piping, hose and solenoid valves.
  • No need for lubrication of the tool. Good for the working environment, especially near paint shops.
  • Due to the newly developed outer rotor servo motor and the composite body, the YOKOTA system e-wrench has the lightest weight in its class.

Reliable and accurate tightening:

  • Faulty tightening detection with maximum accuracy due to the use of an integrated torque transducer and also an integrated angle sensor.
  • During the tightening process, four different variables are measured and monitored:
    Torque – Angle – Time – NÂș. of Impulses.
  • Torque transducer and angle sensor located directly at the front of the main shaft, giving the best accuracy of measurement.
  • Torque transducer measures directly and transmits the signals contactless.
  • The angle sensor is an extremely compact (PAT) rotary encoder that detects both angle as well as direction by 1 degree, signal transmission contactless.
  • Detects cross threads, double hits, contamination, etc.


  • The impulse unit is supported on both ends by ball bearings (PAT.P).
  • The impulse unit has a check valve mechanism (PAT.P) to reduce the oil pressure on the main shaft.
  • For heat suppression of the impulse unit it is equipped with a separate cooling fan.
  • For heat suppression of the motor it is equipped with a cooling fan that reduces motor size (and weight at the same time).
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Electric System Wrenches

Electronic torque control & angle monitoring
  • Controller Features:
  • 20 different parameter settings possible, for a variety of different work pieces
  • Touch screen LCD color display, showing graphs, torque, angle, impulses and more
  • Group management function (counting)
  • Result of tightening output through various interfaces: USB, RS-232C, I/O and Ethernet connector
  • Simultaneous use of two tools on one controller is possible

Sizing Options

See Data Sheet (link above) for full technical specifications

TypeSquare / Hex DriveBolt Capacity mm
E-M5003/8″ Sq.M5 – M6
E-M7003/8″ Sq.M6 – M8
E-M9003/8″ Sq.M8 – M10
E-M11001/2″ Sq.M10 – M12

Operator comfortability:

  • The reaction forces are close to zero due to the use of the oil impulse mechanism, even at high torque bolt tightening.
  • Compared with older models, the number of bolt tightening is improved to 20 bolts/minute.
  • Special feature to prevent cross threaded tightening:
    reversely rotating a bolt to a preset angle at the start of tightening.
  • High speeds: Free speed (bolt run down) of 4800 RPM.
  • High intensity LED light to project on the bolt.
  • Combinations of buzzers and LED (Green / Red) for operator feedback on OK / NG tightenings.
  • Motor speed freely adjustable in the controller.
    For three different speed stages:
    Start of trigger / Run down / Final tightening.