How to Use a Torque Wrench for Tightening Bolts
An operator sets a torque wrench to a specific setting in foot-pounds to tighten a bolt to an exact amount of pressure. Mechanics use torque wrenches to avoid over or under tightening bolts on vehicles to follow the manufacturer specifications. Torque wrenches will operate on standard threaded bolts and on left hand bolts that tighten in a counterclockwise direction.
Other People Are Reading
Instructions
-
-
1
Hold the torque wrench by the handle in one hand.
-
2
Grasp the metal lock ring between the handle and shaft and pull it downwards to the handle. This will unlock the tool settings.
-
-
3
Turn the handle to set the pressure in foot-pounds. Line up the settings on the handle from 0 to 9 and the settings on the shaft from 0 to 9. For example, to set the torque to 37 foot-pounds turn the handle so the 3 on it is in the 0 to 9 range on the shaft. Continue turning the handle until the 3 reaches the 7 on the shaft.
-
4
Grasp the metal lock ring and push it upwards to lock the torque setting in the tool.
-
5
Push a socket on to the end of the torque wrench.
-
6
Place the socket on a bolt and turn in a smooth motion without stopping. The torque wrench will tighten the bolt to the correct setting and then will make a clicking noise. Stop turning the wrench when the clicking noise is audible.
-
1
Tips & Warnings
Do not tighten a bolt partially with a torque wrench and stop the forward motion. This results in friction on the bolt and does not allow accurate readings on the tool.
A clicker torque wrench is the most commonly used because the operator does not need to read a gauge to know when to stop tightening. The clicking noise alerts the operator to the correct pressure on the bolt.
Torque wrenches have a ball on the end of a spring inside the shaft that moves forward to tighten bolts. Reaching the correct pressure drives the ball sideways off the spring so it will no longer tighten. The ball's motion on the inside of the shaft creates a clicking noise.
Take care not to drop a torque wrench on the ground or any hard surface. This action results in the tool being inaccurate in measurements.
References
- Photo Credit torque wrench in box image by Christopher Dodge from Fotolia.com
