Torque wrenches are tools designed for applications that require a specific amount of torque in tightening nuts or bolts. Different types of torque wrenches have different ways of telling you that you have reached the right amount of torque. But before knowing the nitty-gritty of this particular hand tool, let’s first dive through the history of torque wrenches. You can also refer to the following link to find a list of torque wrench reviews. If you’re looking for high-quality, signature hand tools, you can check them online.
How Do They Work?
There are several kinds, including click, beam, and dial. The click type, which employs a ball and spring mechanism, is the most accurate. An adjustable screw thread pre-loads the spring before applying force to the ball. The ball clicks out of its socket when the spring’s force is exceeded. By glancing at the pointer and the indication it displays on the scale, it is possible to interpret the arm of the beam type, which indicates the amount of force being applied. The dial type, as its name implies, uses a dial indication to track the amount of applied torque.
How Are They Used?
Torque wrenches are used to precisely apply and measure the amount of torque on nuts, bolts, and other fasteners used in a variety of sectors, including construction, the automobile industry, the manufacture of thousands of various types of machinery and devices, and the household. To ensure that the various bolts, nuts, and other fasteners are tightened adequately in order to preserve safety and dependability and to meet performance standards, engineers in these many disciplines are given torque values throughout the design process. Without the usage of torque wrenches, many of the everyday necessities we rely on wouldn’t work reliably, which would make life much more difficult.
It’s important to use tools that have been properly calibrated. If it’s been calibrated, it should be demonstrated with a sticker on the tool.
They often have a lock that needs to be disengaged before the handle can be rotated. Once the lock has been taken off, rotate the handle to line up the number on the handle with the center line on the barrel. Then put the lock on to avoid any risk of adjusting the setting when using it.
When using a click torque wrench, use one hand to hold the pivot in place, then the other on the handle. Rotate the tool until it makes an audible noise. As soon as that happens, stop turning, as one click is all that’s needed otherwise the fastener can be overtightened.
Once the tool is no longer needed, position the scale back in its lowest setting, to prevent impacting its accuracy for future measurements.
Refrain from using them on fasteners that have already been completely tightened with a conventional wrench or socket, as it could be that the right level of torque has already been exceeded. Instead, it’s better to loosen the fastener and then re-torque it to the right setting.
How to Maintain
A torque wrench has to be kept dry, well-lubricated, and clean in order to be maintained. This will protect the wrench against rust, corrosion, and damage. When the wrench is not in use, ensure sure the click type has no more than 20% of the range preloaded. Otherwise, the spring may get permanently compressed (take a set), rendering the wrench inaccurate and unusable. To maintain your measurements accurate and trustworthy, you should also get your wrench calibrated on a regular basis.
Patent Applications
It was said that John H. Sharp was the first person who applied for a patent in May 18, 1931. His patent was referred to as a torque-measuring wrench. It was described as “relates to wrenches, and more particularly to one for indicating the amount of force.” Such patent was granted and published on July 9, 1935.
However, there are other articles claiming that it was actually Conrad Bahr who invented the torque wrench back in 1918. This claim states that Conrad designed such torque wrench when he was working for the New York City Water Department. The tool was intended to avoid over-tightening of bolts on water main and steam pipes.
Together with Bahr’s partner, George Pfefferle, the adjustable ratcheting torque wrench was designed and patented in 1935. Pfefferle was then an engineer for S.R. Dresser Manufacturing Co. The two designed a tool that’s equipped with audible feedback and back-ratcheting movement restriction once the required torque was reached.
Continuous Development
Torque wrenches are quite simple and easy-to-use tools. It shouldn’t be surprising that there’s really not much to know about the history of torque wrenches. What’s interesting to note is that the designs from patents were further developed to make them useful for various applications. As a result, there are now many different types of torque wrenches available in the market.
Introduction of Different Types of Torque Wrenches
The beam-type torque wrenches, for one, is said to be developed around late 1920s to early 1930s. Walter Percy Chrysler was then working for Chrysler Corporation when he designed the tool. Such invention was patented in 1938 under the name of Paul Allen Sturtevant.
Sturtevant was then a sales representative for Cedar Rapids Engineering Company and was granted by Chrysler the license to manufacture the beam-type torque wrenches. He was also considered the first person to sell torque wrenches.
From the above-mentioned invention, the dual-signal deflecting beam torque wrench was later developed. It was patented in 1948 by an Australian company named Warren and Brown. The said invention applies torque to a deflecting beam instead of a coil spring. As a result, the wrench is more accurate and has longer working life.
The more advanced electronic torque wrench equipped with angle measurement was filed for patent in 1995. It was the company named Saltus-Werk Max Forst GmbH that applied for said invention.
Electronic Torque Wrenches
As opposed to analog torque wrenches, electronic torque wrenches measure turning force electronically for high accuracy. They are frequently used for applying consistent torque and verifying proper torque on assembled products for safety and quality control purposes. Electronic torque wrenches are also known as digital torque wrenches.
Standard-Head, Electronic Torque Wrenches
These standard-head electronic torque wrenches include auditory and visual indicators to show when the target torque is attained and if the fastener has been overtorqued. They deliver an accurate torque reading on a digital display. Compared to analog torque wrenches, wrenches measure turning force electronically for excellent precision.
Flex-Head, Electronic Torque & Angle Wrenches
These electronic torque and angle wrenches with flex-heads measure both applied angle and torque. Fasteners in confined locations may be reached with the wrench by angling the flex-head. In order to prevent overtightening or undertightening fasteners, they offer an accurate torque reading on a digital display. Unlike analog torque wrenches, these wrenches measure turning force electronically for excellent precision.
Standard-Head, High Accuracy Electronic Torque Wrenches
To prevent overtightening or undertightening bolts, these standard-head electronic torque wrenches contain a high-contrast rotary dial display that displays the amount of torque. As opposed to analog torque wrenches, they measure turning force electronically for great precision.
Flex-Head, Electronic Torque Wrenches
These electronic torque wrenches with flexible heads may be used at an angle to reach fasteners in confined locations. They contain aural and visual indicators to show when the appropriate torque is attained and whether the fastener has been overtorquered. They give an accurate torque reading on a digital display. Unlike analog torque wrenches, these wrenches measure turning force electronically for excellent precision.
Standard-Head, Electronic Torque & Angle Wrenches
These electronic torque and angle wrenches with standard heads measure both applied angle and torque. In order to prevent overtightening or undertightening fasteners, they offer an accurate torque reading on a digital display. Unlike analog torque wrenches, these wrenches measure turning force electronically for excellent precision.
Closing Words
What we’ve shared here are just few of the notable torque wrench developments and patents. Yet, certainly there are other types of torque wrenches that have been developed and were not included here. Regardless of whether they are patented or not, we hope that you will appreciate how a simple hand tool was improved through the years. This history of torque wrenches just gave you an idea of how different principles were applied to design the different types of this hand tool.