Torque Control: Digital Limiters For Impact Wrenches

A digital torque limiter for an impact wrench is a device that prevents over-tightening of fasteners. It is designed to stop applying torque when the correct amount of torque (measured in pound-force per foot, or ft-lbs) is reached, which is indicated by an audible click or a buzzer and LED flash notification. Digital torque limiters are available in different sizes and torque ranges to fit different impact wrenches and applications. They are used to ensure that the correct torque is applied, preventing damage to the fasteners and the material being worked on.

Digital torque wrenches with torque limiting settings

A digital torque wrench with a torque-limiting setting is a handy tool to have, especially when working with automotive parts. These tools are designed to prevent over-tightening of fasteners, which can cause damage to the parts being worked on.

Digital torque wrenches with torque-limiting settings are available in a range of sizes and styles to suit different applications. Some are designed to be used with a standard wrench or breaker bar, while others are cordless or pneumatic for added convenience. When choosing a digital torque wrench, it's important to consider the torque range that you require for your specific application.

The ACDelco ARM602-4A, for example, is a heavy-duty digital torque adapter that offers torque settings ranging from 25 to 250 ft-lbs. It features a buzzer and LED flash notification to indicate when the desired torque level has been reached. Another option is the Ingersoll Rand 2135QTL-2, a torque-limited air impact wrench that delivers a maximum reverse torque of 780 ft-lbs and a forward torque limit of 75 ft-lbs. This tool is designed to prevent overtightening of lug nuts and minimize the risk of damaging wheels.

In addition to these individual tools, torque-limiting extension bar sets are also available. These sets typically include colour-coded torque sticks that allow you to set a specific torque limit for your impact wrench. The Capri Tools 1/2-inch drive torque-limiting extension bar, for example, has a torque limit of 100 ft-lbs.

When using any type of torque wrench, it's important to consider the accuracy of the tool. Factors such as bolt size and grade can affect the accuracy of a digital torque wrench, so it's always a good idea to calibrate your tool and perform regular checks to ensure it is functioning correctly.

Torque limiting impact extensions

Torque-limiting impact extensions are used to prevent over-tightening of fasteners, ensuring consistent torque accuracy. They are designed to be used with impact wrenches and can be used with both standard and thin-wall sockets.

Torque-limiting impact extensions typically come in sets of 5 or 10 pieces, with each extension in the set designed to handle a specific torque range. The extensions are usually colour-coded and engraved with the torque range, making it easy for users to select the correct extension for their needs.

When using a torque-limiting impact extension, it is important to select an extension with a torque rating approximately 20% lower than the desired final torque. The extension is then attached to an impact wrench and used to tighten the fastener with a quick tap. The final tightening should be done with a torque wrench to ensure the correct torque is applied.

Some examples of torque-limiting impact extensions include:

• Capri Tools 30083 Torque Limiting Extension Bar Set (5-piece set)
• Orion Motor Tech 1/2" Drive Torque Limiting Extension Bar Set (5-piece set)
• ARES 70367 Torque Limiting Extension Bar Set (10-piece set)
• Pittsburgh Automotive 1/2" Torque Limiting Extension Bar Set (10-piece set)

Torque limiting sockets

Torque-limiting sockets, also known as torque-limiting extension bars or torque sticks, are used to prevent over-tightening of fasteners. They are designed to work with impact wrenches to tighten nuts to a desired torque spec.

Torque-limiting sockets are solid pieces of metal that look like rigid extensions. They are designed to twist, flex, or bend at a certain torque threshold, preventing further torque from being applied and keeping the nut from being tightened past the intended torque. This is achieved through the use of a clutch mechanism inside the socket that completely releases when the torque limit is reached, even if turning is continued or different tool lengths and adapters are used.

To use a torque-limiting socket, it is important to first calibrate your impact gun to the socket by checking the torque with a wrench. Once calibrated, the socket will absorb the impact of the gun once the torque limit is reached, and the nut will stop turning. This can be identified by an audible "click" or by feeling the socket flex and spring back to normal.

While torque-limiting sockets can save time during the tightening process, they are not exact by nature. Experts recommend using a torque stick to get to about 70% of the desired torque and then switching to a manual method, such as a calibrated torque wrench, to finish. This ensures that the final torque specified value is reached accurately. Additionally, it is important to double-check the settings with a torque wrench once the vehicle is on the ground, as impact gun torque can vary widely, resulting in loose wheels or hardware damage.

Torque limiting extension bars

There are a variety of torque limiting extension bars available, with different numbers of pieces in each set. For example, the Capri Tools set includes five 1/2-in, 8-in long extension bars, while the Pittsburgh Automotive set includes 10 pieces. The Capri Tools set includes bars with torque limits ranging from 65 ft-lbs to 140 ft-lbs, while the Pittsburgh Automotive set includes bars ranging from 65 ft-lb to 150 ft-lb.

Some other features of torque limiting extension bars include visible lasered sizing, carrying cases, and lifetime warranties.

Torque limiting extension and impact socket combo sets

Benefits of Torque Limiting Extensions and Impact Sockets

• Prevent Over-Tightening: Torque limiting extensions are designed to release automatically when a preset torque limit is reached, preventing over-tightening and potential damage to fasteners or equipment.
• Improved Precision: With torque limiting extensions, you can tighten fasteners to a precise torque value, ensuring that your work meets specific requirements or manufacturer specifications.
• Versatility: By using different combinations of torque limiting extensions and impact sockets, you can work with a wide range of fastener types and sizes.
• Ease of Use: Many torque limiting extensions and impact sockets are colour-coded, making it quick and easy to select the right tool for the job.

Things to Consider

• Torque Range: Ensure that the torque limiting extensions in your set cover the torque range you need for your specific applications.
• Socket Sizes and Types: Check that the impact sockets included in the set are compatible with the fasteners you typically work with. Look for sets that offer a range of socket sizes and types.
• Durability: Opt for impact sockets and torque limiting extensions made from high-quality materials, such as chrome-molybdenum (Cr-Mo) steel, to ensure durability and a long service life.
• Storage and Case: Consider purchasing a set that includes a storage case to keep your tools organised and protected when not in use.

Examples of Torque Limiting Extension and Impact Socket Combo Sets

• Astro Pneumatic Tool 78818 8-Piece Set: This set includes four torque limiting extensions (90, 100, 110, and 120 ft/lbs) and four protective lug nut impact sockets (17mm, 19mm, 21mm, and 7/8”).
• Powerbuilt 8-Piece Set: Featuring a free-spinning grip handle, this set comes with four torque limiting extensions (80, 100, 120, and 130 lb-ft) and four wheel protector lug nut impact sockets (17mm, 19mm, 21mm, and 22mm).
• Prokomon 8-Piece Set: Designed for impact torque applications, this set offers torque limiting extensions ranging from 90 to 120 ft-lbs and deep impact sockets.
• Neiko 02453A 8-Piece Set: A combo set that includes torque limiting extensions and deep impact metric sockets, suitable for a 1/2" CrMo drive.

Frequently asked questions