A torque wrench is a tightening tool designed to apply a specific amount of torque to bolts, nuts, and other fasteners. They are typically found in industrial trade, construction, and automotive shops. This article will be going through all the torque wrenches and how to use them.
How to Set a Torque Wrench
Torque is the unit of measurement of rotational force. The units to measure the level of torque are lb-ft (pound-foot) and Nm (Newton-meter). Most machines using bolts and nuts will have the required torque specification printed on them.
From the settings, you can easily increase or reduce the level of torque to the correct amount you need. This is done by turning the handle clockwise to increase it and counter-clockwise to lower it. You can determine the amount of torque you are on through the scale on it. Some brands have a display screen in place of the scale.
How Does a Torque Wrench Work?
The Basics
We do not recommend you use just one torque wrench to adjust every type of fastener. To understand why you cannot do that you need to understand how fasteners work. Fasteners have threads that form a wedge, which is the simplest type of tool.
The inclined plane is wedged into threads that allow it to apply the force along the length of the bolt. This process essentially turns the bolt into spring full of tension. In addition, this creates tension where the clamping force between the two parts is greater than the load exerted between them. The tension between the two parts ensures the two pieces will never spontaneously come apart.
Friction has to be taken into account when fastening a bolt. A lot of energy expended is used to combat friction and a scanner will not be of much use. Using a torque wrench helps overcome the friction and ensures your fasteners are tighter and more secure.
How is a Torque Wrench Different from a Spanner?
Though the spanner and the torque wrench serve the same purpose, they are different in that the torque wrench requires very specific values. For safety reasons, bolts and nuts used in certain industries like aviation and motor vehicle manufacturing require a specific value of torque. This is done for safety reasons and it ensures that important components do not come apart.
In such cases, applying too much torque might damage the threads and make them less effective. As such, if there is a need to secure the bolts and nuts, use a torque wrench with a precise torque level instead of an ordinary spanner to improve workplace safety and lengthen the longevity of your equipment. You can also use your torque wrench to loosen bolts, not just tighten them.
How Much Torque Do I Need?
Typically, the amount of torque you need to work on any kind of machinery will be labeled on the machine. If you cannot find the proper torque specification, then proceed to check for them on the company’s website. Using the wrong torque requirements could result in the fastener being either too loose or tight to the point of damage. This can be dangerous in case of a fault.
How Much Torque is Required for a Spark Plug?
Since cars are the most popular mode of transport in the United States, a lot of people work on their spark plugs. There are different types of spark plugs, all designed for use in different engines. As such, there isn’t any figure that can best work for all types of spark plugs.
When working on any car ensure you seek out the proper torque setting requirements to safely fasten it to the engine with the right level of torque. Any automotive torque wrench could easily solve this problem.
How Much Torque is Required for Wheel Nuts?
There is a common assertion that the tighter wheel nuts are, the safer they are. However, this is not the case. Loose wheel nuts can be dangerous should they come off when driving, while over-tightened wheel nuts can also be just as dangerous. Over tightened fasteners could result in damage to the threads and make them less reliable and negatively affect the torque level.
Every car has a specified actual torque value for wheel fasteners. This should act as a guide for the amount of force you should be using. Tightening the bolt past the manufacturer’s recommendations will likely stretch them. Once stretched past their limit, they can shear, lowering the fastener’s reliability.
How to Set Up and Use your Torque Wrench
Before anything, the first thing you should do is find out what the required torque value is. You can find this figure in your user manual, or on the company website in the case of some brands. Make sure you get the right figure. Most scales will have the foot-pounds on one side and Newton meter on the other.
Here is how you use a torque wrench:
- At the bottom end of the torque wrench, you can identify a knob. Once you loosen it, the handle will let the handle twist back and forth.
- If you need 100 lb. ft., you should rotate the handle until the “0” mark meets the 100 lb-ft mark.
- Once you have the torque of your choosing, tighten the lock nut back up. This is a crucial step to using a torque wrench.
- Place the torque wrench in such a manner that the socket holds the nut.
- Steadily place it on the lug nut, proceed to firmly grip its handle, and then tighten it.
- When you finally hear a click sound the torque you had set has been met.
Here are some points you should keep in your mind:
- Whenever you hear a click sound as you are turning your torque wrench, another click is all that is needed for the bolt or nut to be over-tightened.
- When tightening fasteners, do not go all the way with the torque wrench. Do most of the work with a simple ratchet then finish it off with a torque wrench to get the required torque.
- If the socket is not deep enough you may need to use an extension.
- Make sure the torque wrench is always handled with care. Ensure it is safe in its supplied case when it is not in use. This will prevent any unnecessary knocks and bumps that could negatively impact its accuracy and calibration.
- When not in use, ensure you loosen it to its lowest point; this helps keep the calibration a lot longer because there isn’t much force on the spring.
- Ensure your torque wrench goes through control and calibration at least annually. This ensures the wrench torque’s accuracy reading each time you use it.
How to Properly Calibrate a Torque Wrench
To get proper use of your torque wrench, make sure it is well-calibrated beforehand in the torque settings. You should get a professional to calibrate your torque wrench to ensure it keeps the torque level under control.
The rate at which you do calibration is not tied to the amount of time that has passed. It is much more dependent on the number of uses you have made since the last calibration. As a rule of thumb, you should perform your torque calibration after every 5000 clicks or after about a year.
Types of Torque Wrench
A torque wrench is a very useful tool. As such, there are other various kinds of wrenches to solve even more specific problems. Here are three of some of the most popular ones:
Click Torque Wrench
These are some of the most versatile wrenches on the market, making them a go-to for most users. With a spring-loaded lever, they can be adjusted by twisting the handle until it makes a click sound to indicate it is at the appropriate torque. You should only keep applying force until the lever breaks, which indicates the desired torque has been accurately achieved.
Most click torques are for ratcheting and can be used for tightening or loosening. Keep an ear out for the click sound; you should only hear it once, any more and you would be over-tightening it. These wrenches come in a variety of torque limits and are great for hard-to-reach places.
Most click wrenches have their calibration in foot-pounds, although you can get them in inch-pounds or Newton Meters. Many of these models have head drive sizes that range from 3/8 inches to 1/2 or 3/4 inches.
These wrenches’ torque ranges can be between 10-2000 ft-lbs. The typical torque range for 3/8-inch square drive sizes is 10-150 ft-lbs. 1/2-inch square drive sizes, on the other hand, have a range of 30-250 ft-lbs. Lastly, the 3/4-inch bits torque rage is 100-600 ft-lbs.
Pros
- They are quite easy and straightforward to use
- These wrenches come with a ratcheting mechanism
- Their clicks are audible even in noisy places
- Very affordable
- Excellent for quick use in tightening or loosening bolts
Cons
- They aren’t highly durable
Digital Torque Wrench
These torque wrenches do not feature any moving parts but instead use electric sensors. They use a digital display to communicate torque measurements being applied. All you need to do is dial in the torque settings and go to work. Once the torque requirement is met, lights on the wrench will flash or keep beeping. Some digital wrenches have memory sticks to save readings.
As you can see, these torque wrenches are designed to make loosening or tightening bolts and nuts easier. They provide accurate readings, and their design allows you to reach small spaces. Digital torque wrenches are simply great for daily use.
However, you will have to pay more to get them. Due to their many features and modern build, they come at higher prices than other torque wrenches. Moreover, you must ensure you recharge them or change their batteries regularly when they run out of power.
When you get one, store it in its shell case for protection. Storing them poorly or with other tools can damage them.
Pros
- They have alert systems for notifying you when you reach set torque limits
- You can preset target torque limits
- Provide several torque measuring units
- Are excellent for day-to-day use
- They are useful in heavy-duty applications
Cons
- You need to recharge them regularly or replace the batteries
Beam Torque Wrench
These are the most basic form of torque wrenches which makes them the easiest wrench to use. They are typically used for precise, exact tightness applications, particularly when making cars. They feature two beams. One lever is used to apply torque to the fastener being tightened and the second is attached to one end of the wrench head allowing it to serve as an indicator beam.
Pros
- Highly accurate
- Simple and easy to use
- Can measure torque in both directions
Cons
- It needs constant calibration for it to maintain high accuracy levels
Dial Torque Wrench
These are the most accurate of all types of wrenches despite using an analog scale. They have a large, easy-to-read display and feature a dual-scale dial to make it easy to read the torque measurements. This makes it a great tool for loosening and fastening bolts which guarantees torque accuracy.
Pros
- High accuracy levels
- Smooth inner working mechanisms
- Excellent for automotive use
Cons
- Difficult to use in tight spots
Factors to Consider When Buying a Torque Wrench
Getting the right torque requires the assessment of various factors such as the cost and storage requirements of the wrench, their head types, drive sizes, and torque range. Let’s take a closer look at why each of these factors matters.
Cost and Storage
As discussed above, there are four main types of torque wrenches, with the most common being the click style wrenches. Each type requires different calibration methods, and they are stored differently.
For instance, you should ensure it’s at its lowest setting to minimize calibration problems when storing a click wrench. Digital wrenches, on the other hand, need to be stored inside their special hard-shell cases for safekeeping. Also, digital toque wrenches cost more than the other types and need regular battery replacements to run properly.
Head Type
Although many torque wrenches come with fixed heads, nowadays, some brands have flexible or reversible heads. The flexible models are great for tight spots as they can pivot 180 degrees. Those with reversible heads make it easy to switch between right-handed and left-handed fasteners.
Drive Size
Drive sizes are the bit sizes you can use with your torque wrench. It would be best if you went for torque wrenches that support the commonly used sizes like the 3/8- and 1/2-inch bits.
Torque Range
Each torque wrench comes with the torque range that it can handle. The range is determined by its size and length and is normally indicated as lb-ft. These torque ranges fall anywhere between 0-300.
Conclusion
In conclusion, before you begin working with any bolts, screws, or nuts with a torque wrench, ensure you check the torque specification for it. Whether you are working with a cylinder head, shock absorbers, or oil filters, most manufacturers will have the specifications printed on the item.