The Different Types of Torque Wrenches

Little, but mighty tools for getting the right torque

The integrity of any threaded fastener is only as good as the guy who installs it. Meaning, of course, that if you over- or undertighten a bolt, you're headed for trouble. The question is, how do you know if the bolt in question is too tight, not tight enough or just right?

Torque wrenches
Torque wrenches like the ones above help you get the proper level of torque and help measure torque for accuracy. The three different types include beam, clicker, and dial-type torque wrenches.Photography by Mark Zimmerman

All threaded fasteners have a recommended torque setting you can find in your bike's shop manual or on a generic torque chart. But knowing the correct torque is only half the battle; you still need some way to measure it. That way is a torque wrench. Torque wrenches are available in three common styles. The most basic is the beam type. These use a simple pointer and scale to indicate the torque being applied. Next is the "clicker." Clickers use a micrometer-type scale built into the handle. The handle is rotated to a preset torque, say 10 foot-pounds. When the correct torque is reached, the wrench releases with an audible click. At the top of the food chain are dial-type torque wrenches. These incorporate a direct reading gauge that may be zeroed and a "tattle tale" to insure that the reading is dead-accurate every time. When selecting your torque wrench you'll need to decide which style you prefer, the appropriate drive size—1⁄4, 3⁄8 and 1⁄2 drives are the most common—the torque range and whether you want a wrench calibrated in inch-pounds, foot-pounds or Newton-meters of torque. The most versatile, and the one I'd recommend, would be a 3⁄8-drive, beam-type wrench with a range of zero–75 foot-pounds. Once you get in the habit of using it you'll wonder how you ever got along without it.