The Essential Torque Wrench

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A torque wrench is a tool which is adjustable to a certain level of force, measured in either foot pounds (lbf / ft) or kilogram metres (kgf / m). This simply means that a setting of 10 ft / lbs equates to ten pounds of force at a distance of one foot from the object being tightened.

Serious, expensive and extremely inconvenient damage results from nuts, bolts and screws being overtightened. Threads strip, bolts snap and as mostly the threads are cut into aluminium engine castings, a stripped thread generally means removing the engine and having a specialist workshop try and repair the damage - and this isn't always possible. A stripped thread may well mean a new crankcase.

A component being undertightened is just as dangerous as it might come loose, damaging itself or its neighbours, or otherwise not work properly. You can imagine the resultant chaos if a nut inside the engine comes off and drops into the spinning crankshaft or gearbox ...

TWs take all the guesswork out of tightening things. It's an invaluable part of any mechanic's toolkit, and just one saved stripped or broken thread means that the tool has paid for itself. It will save your bacon dozens of times in its life. Buy one, plus any adapter pieces you need to make it fit your range of sockets. For example the TW may be a 1/2" square drive but if your sockets are 3/8" drive you will need a cheap adapting piece.

Models of TW vary, but typically (left) it will have a winding wheel at the handle end which is turned one way or the other to adjust it, and a window which shows the desired setting. As it is attached to the object being tightened and force is applied, it gives a pronounced "click" and "gives way" when the preset force has been met. As soon as you hear the click and feel the "give", stop tightening. The object is now correctly tightened. That is why TWs are sometimes called "click-stop" wrenches.

This link takes you to a search on eBay for "torque wrench". For most Honda motorcycles, the lowest setting you need is 6 ft / lbs, and the highest is 68 ft / lbs. A TW in the range 6 - 40 ft / lbs will do almost everything you need to do. Cost approximately £30-£70.

There is a cheaper, nasty model which instead of a click-stop has a straight bar which does not move when you tighten the object, but shows a pointer against a graduated scale instead. Do not buy one of these - they are not accurate enough, especially for the small nuts and bolts. The posh expensive TWs have a digital display, smart move if your budget (£80-120) runs that far.

Always reset your TW back to the minimum setting when you have finished with it.