torque-wrenches are used by a variety of professionals including mechanics and machinists, along with does it yourselfers. torque-wrenches are used in applications in which the amount of torque to which the bolt is tightened is critical. Over tightening bolts can cause the bolt to snap making removal extremely difficult. Under tightening a bolt can cause the bolt to come out of its intended hole due to a vibrating machine or engine. A loose bolt can pose a danger to the car, tool or project on which you are working. It can cause failure to motors and tools or injury to those operating it or near it.

Using a torque-wrench allows the user to tighten the bolt to the specifications set forth by the manufacturer. The manufacturers specs shouldn’t be used as a guideline, they should be strictly adhered to. Engineers worked on the specs for a long time to determine what is safe and what is dangerous. They didn’t just pull the numbers off the top of their heads. Using a torque-wrench will allow the bolt to keep the necessary tension to maintain good working order and safety.

There are many types of torque-wrenches ranging from the simple and common to the more complex. Choose the type of torque-wrench based on your needs in the particular job or project.

Electronic torque-wrenches

Electronic torque-wrenches are among the most precise. Typically, electronic toque wrenches are battery powered. The user sets the value on a digital display and tightens the bolt. When the desired torque is reached the electronic wrench will signal. Some models are programmable. Standard electronic torque-wrenches are usually used for car, boats, RV’s, airplanes, motorcycles and small type machine repairs. Electronic torque-wrenches are available in a wide variety of sizes to fit many applications.

Click Wrenches or Micrometer

Of all torque-wrenches, the click wrench or micrometer is by far the one used the most often. So named because when the wrench meets the desired torque, it makes a loud click sound.  You can also feel the click in your hand as you are using which is valuable to those working in a noisy environment. If the person using a click wrench doesn’t pay attention to the click or doesn’t maintain his or her tools properly, it is possible to over tighten the bolt regardless of the clicking noise. When using a click wrench or micrometer pay attention to the noise it makes and feel for the click to precisely tighten or loosen bolts.

Cam Over torque-wrenches

Cam over torque-wrenches typically will slip away once the desired torque is met. Cam over torque-wrenches are a good choice when precision is completely necessary. They are more accurate and precise than click wrenches. Cam over torque-wrenches are considered a precision tool. Generally, they are used for machinery and moving parts where proper torque is critical to the operation.

No Hub torque-wrench

A no hub torque-wrench is generally used by plumbers. The wrench has a T shaped handle and used to seal a coupling at a waste pipe. The torque setting is calibrated by the wrench manufacturer and will slip in the case of over tightening or too much torque. It work as a ratchet and clutch wrench.

Beam Type torque-wrench

The beam type torque-wrench has a top just under the handle that looks like a small scale. A metal pointer moves with each revolution of the wrench to indicate the amount of torque that is pointed to on the scale. You have to watch the metal pointer and pay attention to the number it is pointing at to determine the torque.

Angle torque-wrenches

Angle torque-wrenches as the name suggests allow you to drive a bolt at an angle. Angle torque-wrenches come in a variety of types ranging from electronic to click wrenches to cam over models. Angle torque-wrenches typically have a straight shaft that bends and has a wrench at the end. Angle torque-wrenches allow a bolt to be tightened to the correct torque even if the bolt head doesn’t face you head on. These are particularly useful when working on cars, RV’s, boats and other machinery.

TorqueWrench Tips

torque-wrenches need to be treated with care in order for them to maintain their precision and accuracy. Tossing a torque-wrench from five feet away into your tool box is never a good idea.

Through use and over time torque-wrenches will have to be recalibrated for them to remain accurate and precise.

The most common torque-wrench most people use is a lug nut tightener for their cars. Think about how important it is to have the correct torque on lug nuts. Over tightening a lug nut can cause the threads to snap. Under tightening a lug nut can cause the nuts to spins off while driving down the highway at 55 miles an hour

Manufacturers express the amount of torque necessary in foot pounds or ft.-lbs as many will write it.

Before tightening a bolt with a torque-wrench, always clean it. Wipe away oils and grease with a grease cutting agent and dry the bolt head thoroughly. If there is rust on the bolt head, use a small wire brush to scrub away the rust and corrosion. Finish wiping of small specs and rust dust with a clean rag. Grease, oils, rust and corrosion can throw off the precision of a torque-wrench which makes working with clean parts very important.

Read the manufacturer’s instructions before tightening a bolt to determine if oil lubrication is necessary or unwanted. Depending on the application some may call for lubrication while others may call for a dry surface.

Every bolt head has a marking that designates the highest amount of torque a bolt can tolerate. Never use bolts that don’t have a marking on the top for any type of precision equipment. Bolts that don’t have markings are more likely to break or strip under the stress of high torque.