4Installing side grip (Fig. 2)For 6906 onlyFit the side grip into the groove on the middle of the ham-mer case and fasten securely.Selecting correct socketAlways use the correct size socket for bolts and nuts. Anincorrect size socket will result in inaccurate and incon-sistent fastening torque and/or damage to the bolt or nut.Installing or removing socket1. For socket without O-ring and pin (Fig. 3)To install the socket, push it onto the anvil of the tooluntil it locks into place.To remove the socket, simply pull it off.2. For socket with O-ring and pin (Fig. 4)Move the O-ring out of the groove in the socket andremove the pin from the socket. Fit the socket ontothe anvil of the tool so that the hole in the socket isaligned with the hole in the anvil. Insert the pinthrough the hole in the socket and anvil. Then returnthe O-ring to the original position in the socketgroove to retain the pin. To remove the socket, followthe installation procedures in reverse.OPERATIONFor 6906 onlyAlways use the side grip (auxiliary handle) and firmlyhold the tool by side grip and switch handle during opera-tions.The proper fastening torque may differ depending uponthe kind or size of the bolt, the material of the workpieceto be fastened, etc. The relation between fasteningtorque and fastening time is shown in the figure.Hold the tool firmly and place the socket over the bolt ornut. Turn the tool on and fasten for the proper fasteningtime.NOTE:• Hold the tool pointed straight at the bolt or nut.• Excessive fastening torque may damage the bolt/nut orsocket. Before starting your job, always perform a testoperation to determine the proper fastening time foryour bolt.The fastening torque is affected by a wide variety of fac-tors including the following. After fastening, always checkthe torque with a torque wrench.1. Voltage• Voltage drop will cause a reduction in the fasteningtorque.2. Socket• Failure to use the correct size socket will cause areduction in the fastening torque.• A worn socket (wear on the hex end or squareend) will cause a reduction in the fastening torque.3. Bolt• Even though the torque coefficient and the class ofbolt are the same, the proper fastening torque willdiffer according to the diameter of the bolt.• Even though the diameters of bolts are the same,the proper fastening torque will differ according tothe torque coefficient, the class of bolt and the boltlength.4. The use of the universal joint or the extension barsomewhat reduces the fastening force of the impactwrench. Compensate by fastening for a longerperiod of time.5. The manner of holding the tool or the material ofdriving position to be fastened will affect the torque.700600500400300200100(7,140)(6,120)(5,100)(4,080)(3,060)(2,040)(1,020)0 1 2 3 4 5 6 7 8For 6906For 6905BRated voltage90% of rated voltagesecondsN•m (kg•cm)