The invention relates to electrical insulation of an electrosurgical instrument. The present invention provides a surgical tool comprising: a drive housing; an elongated shaft extending from the drivehousing; and an end effector disposed at the distal end of the elongated shaft and having a jaw and a jaw holder that secures the jaw. A wrist portion couples the end effector to the elongated shaftand includes a distal connection fork having a shaft member rotatably mounting the jaw holder on the distal connection fork. An electrical conductor extends from the drive housing and supplies electrical energy to the jaws via a power supply conductor. At least one of the jaw holder and the shaft member is made of a non-conductive material that insulates the distal connection fork from the electrical energy provided for the jaw.