A beam–type torque wrench is a tool that is highly susceptible to breakage. Quite simple in form, this tool consists of a long lever arm that stretches from the handle to the wrench’s head. The torque wrench is made to bend elastically when responding to applied torque. A second bar, used as the indicator, is connected to the head and sits parallel to the lever arm. This bar doesn’t bear any torque and, therefore, stays stationary. The torque wrench has a calibrated scale to measure the amount of applied torque, measured by the bend on the main lever which, in turn, moves the scale under the stationary bar. The most common problems seen in beam–type torque wrenches are related to the pointer beam. This beam may either fall out of calibration or even rest on the scale, hampering the accuracy of the tool. Read on to learn how to repair various problems with your beam-type torque wrench.
Fixing the Calibration
Beam–type torque wrenches, like all other torque wrenches, regularly fall out of calibration. You can re–calibrate the torque wrench using a simple re-calibration technique that follows the principle of deflection. Inspect the pointer when the torque wrench is at rest. If the wrench is out of calibration, the pointer will be either on the right or left of the zero marker.
To re–calibrate, simply bend the torque wrench to bring the pointer back to zero.
Floating the Scale
At times, the pointer may lie against the surface of the scale. In such cases, the indicator beam does not move as freely as it should.
Using a lever between the two beams is the correct way to fix such problems with your pointer in a beam–type torque wrench. Insert the lever between the two beams and pry them little–by–little. Keep checking the scale and the pointer while doing this, as your beam–type torque wrench returns to perfect calibration.
Bending the pointer, to fix this problem, will not affect the accuracy of the readings on the beam–type torque wrench at all.
Breaking a Torque Wrench
In certain cases, especially when you apply more torque than prescribed by the manufacturer or twist the wrench in the wrong direction, there is a chance that the calibration and accuracy may get affected. In worst case scenarios, the beam–type torque wrench may physically break.
In the latter case, there isn’t anything you can do to repair the torque wrench. Your only option is to replace it with a brand new torque wrench as a broken or mended torque wrench will not have the same strength in structure as a completely healthy piece.
Most beam–type torque wrenches come with a lifetime warranty however that is only in the case of usage within the prescribed limits. The steel does not display signs of fatigue or other damage despite years of usage. Storing the wrench safely and maintaining it regularly ensures easy repair for a broken beam–type torque wrench.