Only a very few species create and use tools. Chimpanzees strip the bark from a twig and stick it down a hole to scoop out termites for eating. Egyptian Vultures use a rock to smash open Ostrich eggs and Green Herons will toss a pebble into a pond to lure fish to the surface. But the all time champion of tool usage is the human species; if Stanley Kubrick’s movie “2001: A Space Odyssey� basic premise is correct, the assent of modern man is a direct result of our primeval ancestors discovering the use of tools. Nearly everything we touch in our life can be considered a tool and we use them without much thought about the process. The At Home Mechanic knows just how important tools are for enjoying our automobile hobby and has a large investment in a wide variety of hand and power tools.
It is not necessary to have a huge collection of tools to begin working on cars, a generic set of wrenches, sockets and screw drivers will get you thorough most jobs you will tackle in the beginning. And although you can “get by� with the basic hand tools for nearly every job, there is one specialized tool that has no replacement and should be included in your basic tool set. Very soon in your journey through the automobile hobby, you will be faced with the need for a Torque Wrench.
A Torque Wrench is a ratchet handle with a device built into it for precisely measuring the amount of torque (or twist) you are applying to a nut or bolt. In many situations it is necessary to put just the right amount of twist on a fastener; too little torque will not secure the part properly and too much torque can cause damage or binding of rotating parts. A Torque Wrench of dubious precision can be bought inexpensively at discount stores, and highly accurate versions with digital read-outs can cost as much as $1,000. Cheap tools seem like a bargain, but in the long run it is always best to spend a little extra money to buy quality tools the first time.
There are two basic designs for a Torque Wrenches: A bar/dial design that has a pointer parallel to the main shaft of the wrench and crudely indicates that amount of torque being applied in foot-pounds or metric measurements. And an internal spring-loaded version that will allow on the amount of specified torque to be applied and then will make a clicking sound to indicate that the right value has been reached.
A Torque Wrench is a precision tool that has been calibrated at the manufacturer to deliver exactly the correct value. To maintain that precision it is necessary to use them and maintain them carefully. When you are tightening a fastener (never use them to undo bolts), keep an even turning speed. Do not stop mid stroke and ratchet the wrench a little bit. The force needed to overcome friction will give you an incorrect torque. When you are done using a spring loaded Torque Wrench, return the wrench to the lowest setting on the handle and relax the tension on the internal spring. If you do not relax the internal spring you are effectively stretching it out of calibration. And use care to not drop a Torque Wrench, it can break and/or need to be recalibrated. Professional mechanics that earn their livings with Torque Wrenches have them recalibrated on a regular basis.
Invest wisely in your Torque Wrench and then take good care of it.