Micrometer torque wrenches are specifically designed to provide the user with more than just a visual reference when the desired torque level has been applied with the tool. Most torque wrenches of this type provide an audible signal and/or physical impulses when the correct amount of torque has been attained. A micrometer torque wrench can provide the user with a more accurate way of measuring actual torque applied compared with a standard torque wrench.
Things You'll Need
- Fastener (nut or bolt to be torqued)
Unlock the torque wrench by holding the base of the handle grip with one hand, then turning the lock ring clockwise until it stops. The lock ring is usually located at the top of the handle grip.
Rotate the handle grip until the "zero" on the thimble scale (imprinted on the top of the handle grip) reaches the number representing the desired torque value to be applied. Torque value to be applied is read from the scale imprinted on the main tool shaft. When you repeatedly twist the handle clockwise, the "zero" mark on the thimble will slowly advance up the main tool shaft. The more you twist it, the higher the the thimble will advance up the shaft. Stop twisting when the torque value you want is directly above the "zero" imprinted on the handle. For example, to apply 180 foot-pounds of torque, stop twisting when the "zero" is aligned with "180" on the main tool shaft.
Keep rotating the handle grip slowly if the torque value desired is somewhere between two numbers printed on the main scale. For example, if you want 190 foot-pounds of torque, twist the handle to 180 foot pounds, then twist the handle another 1/2 turn to add 10 more foot-pounds. (Each full revolution of the handle will advance the thimble scale 20 foot-pounds.)
Lock the torque wrench (so that the correct settings are retained) by holding the handle grip with one hand, then turning the lock ring counter clockwise until it stops rotating.
Torque the desired fastener (nut or bolt) to the pre-set torque level by attaching a socket to the end of the torque wrench. Position the socket squarely onto the head of the fastener. Grasp the middle of the hand grip, then apply an even force, as you would would with any regular socket or wrench. Try to keep the socket as straight as possible on the nut or bolt to get an accurate torquing.
Continue applying a force to the handle, and allow the handle to ratchet like a normal socket wrench if you need more pulling leverage. Once the desired torque has been applied, you will feel and/or hear feedback from the torque wrench that the correct torque has been attained. Stop applying force, and remove the torque wrench from the fastener.
Tips & Warnings
- Accurate torque reading can only be attained if the torque is applied in perpendicular motion to the handle, and if the handle remains square and true above the fastener in all planes.