The 10 most important considerations when selecting your next hydraulic torque wrench

Hydraulic torque wrenches have come a long way since they were first introduced in the early 1960s. Advancements in technology have created countless options, features, and benefits to decipher – making it much harder to have confidence in your final tool selection.

If you are a seasoned bolting specialist, then you will know the must-have features needed to complete your specific bolting projects like a pro. However, if you are new to bolting, selecting the right hydraulic torque wrench for your job requires understanding the choices available. The design and features of each series of torque wrenches are tailored to suit different applications. Below are key considerations when selecting a torque wrench for your unique job.

Torque Wrench Basics

Hydraulic torque wrenches create the exact torque output or torque load necessary to loosen or tighten the threads of a nut and bolt for a leak-free joint. A hydraulic torque wrench is comprised of two primary parts; square drive socket combination or hex cassette and a drive unit which is actuated by a hydraulic cylinder. A complete hydraulic torque wrench system includes a hydraulic pump with a coupler and hose. Actuating the pump advances the torque wrench.

Consideration 1: Square Drive or Low Profile

A square drive hydraulic torque wrench shares the same principle as the torque wrench you might have in your garage. It works with different sized sockets to fit the nut to be tightened or loosened.

A low-profile torque wrench uses interchangeable cassettes (sometimes referred to as ‘links’). This type of tool is commonly used in the oil and gas industry where clearance around the nut is often restricted.

Consideration 2: Heavy User or an Occasional User

Most hydraulic torque wrenches from reputable manufacturers are robust, reliable, and fit for purpose. Heavy users with repetitive, heavy-duty applications often opt for highly reliable models such as the Enerpac S Series (square drive) and W Series (low profile). At this level, expect hassle-free ownership, superior quality, and extra features, such as quick-change cassettes.

Consideration 3: Versatility and General-Purpose

If you want fewer tools that serve a wide range of applications, then consider a two-in-one general-purpose tool. Good examples are the Enerpac RSL Series and the aluminium-bodied HMT Series. Both include modules for square-drive and low-profile applications.

Consideration 4: Size and Torque Output

Will it be powerful enough and the right size to do the job? Each hydraulic torque wrench works with many different cassettes or sockets. But there are many different drive heads to choose from. Each has a different maximum torque output and is designed to cover a certain range of hex sizes. You should understand the minimum and maximum sizes you want to cover. Then check specifications on the manufacturer’s website.

The right tools used for controlled bolting can make the difference between your job running efficiently or encountering costly delays. There are many application considerations and choices. Enerpac can advise on the best torque wrench selection.

Consideration 5: How much do I need to invest in a hydraulic torque wrench?

Opinions vary. Are you thinking short term or long term?

If weighing up the total cost of ownership over the long term is your preferred approach, then build maintenance into your calculations. Higher quality products may be a slightly higher investment, but they will require much less maintenance and repair over time.

If you do not intend to use the tools frequently, then mid-market products may be a better solution. This category includes interchangeable and two-in-one modular designs – enabling you to cover a wide range of applications with fewer tools.  Examples adopting this approach include the Enerpac RSL Series. These models offer cost-effective compatibility with low profile to square drive, or vice versa, using the same drive unit.

Are you looking to upgrade your torque tools, but want to continue using your existing cassettes and drive units? Select a modular torque wrench design, such as the Enerpac HMT Series. These models use drive heads that are interchangeable with cassettes from a variety of leading brands.

Interchangeability works the other way around too. Buy an Enerpac HLP cassette and it will work with drive units from other many other brands.

Consideration 6: Convenience, Safety, and Easy Operation

It is important to understand how to easily operate your torque wrench for maximum safety and productivity. Features such as safety handles, swivel hoses, tether points, no-drop features, and quick-change cassettes provide improved usability and safety. Each of these can make a huge difference when working in challenging conditions offshore, or up high on a wind turbine tower.

Consideration 7: Steel or Aluminium?

This is rarely an obvious factor when people choose a hydraulic torque wrench. A torque wrench with a body constructed in either material will be robust enough for most applications. However, it is worth noting that steel is stronger, but marginally heavier than aluminium. Steel torque wrenches also tend to be smaller – allowing them to fit more applications.

Consideration 8: Cassette Choice

If you select a low-profile type of torque wrench, you will need to choose cassettes to suit various A/F hex sizes (Across/Flats). For each drive head there are many available to suit both imperial and metric sizes. Note that different ranges of torque wrenches from the same manufacturer often have dedicated cassettes. Do not assume all are compatible with each other. But as mentioned earlier, the HMT Series is an exception and is compatible with cassettes from a variety of manufacturers.

By default, cassettes for low profile torque wrenches are designed for tight spaces. There are other more slimline types available. These are perfect for applications where flange nuts are positioned very close together.

Consideration 9: Accessories

There are numerous accessories available for hydraulic torque wrenches. These add additional safety, certainty, convenience, and extend the number of applications. Examples include sockets, back up spanners, different sized reaction arms, safety handles and reducers.

Consideration 10: Torque Wrench Pumps

Pairing your hydraulic torque wrenches with the most compatible pump for your application will ensure optimal speed and performance. Choose from ATEX-certified air-driven, battery-powered or electric pumps all designed to meet the needs across a variety of controlled bolting applications. Your pump pairing is just as important as selecting your torque wrench.

Choosing a hydraulic torque wrench requires careful consideration. If you need any guidance, contact an Enerpac Bolting Specialist.

Why Choose an Enerpac Torque Wrench?

Putting an Enerpac torque wrench to work for your bolting application is a sound choice. Choose from a full portfolio of solutions to meet your needs from the most demanding applications in the harshest environments to routine or occasional use. For those unique applications, rely on a custom solution from a trusted brand that builds tools that are designed to perform every time. All Enerpac tools are fully supported by our application experts, calibration & maintenance services (no premium service contract required), rental programs and training.

For more information on Enerpac Torque Wrenches, visit

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