Bolting systems are the basis for many industrial projects, especially in the wind power industry. The safety of the bolting system is fundamental to the proper operation of the wind turbine. Whether it is wind turbine assembly or post-maintenance, special bolting tools for the wind power industry are essential.

Areas Where the Wind Turbine Needs to be Bolted

Nacelles – Bearings and vanes need to be attached with a suitable wrench and tensioner.
Towers – Assemble and maintain tower structures with wrenches and tensioners following the manufacturer’s guidelines
Foundation – Foundation bolts at sea usually use a safe and reliable anchor bolt tensioner, and hydraulic torque wrenches usually handle anchor bolts on land.

However, the bolting system of wind turbines is very complex, and the simple three basic parts do not allow for more accurate tool selection. Therefore, tools should be selected by the following areas, including foundation bolts/anchors, tower section bolting, gearboxes, rotor bearings, yaw bearings, rotor blades, all other bolting applications larger than M16 (2/8″).

Basic Types of Wind Turbine Bolting Tools

Although there are many different types of torque and tension tools for wind turbines on the market today, they can be divided into three basic types: battery-powered and hydraulic-powered. The choice depends on factors such as convenience, cost, and specifications.

Electric Torque Wrench

Electric torque wrenches are battery-powered and are lighter and smarter wrenches. While hydraulic wrenches and hydraulic bolt tensioners have always been the mainstay of the wind power industry, the advantages of electric wrenches are clear. For example, with an electric wrench, the range of torque error can be much smaller because the tool can be locked to a specific torque value. The torque limit on the wrench can be set for multiple jobs simultaneously with an accuracy of ±3%. It is estimated that electric torque can save 33% of the time compared to hydraulic torque. A battery-powered wrench powered by a lithium-ion battery can put out 5000 foot-pounds of torque and tighten over 90 bolts with a single battery!

Hydraulic Torque Wrench

For industrial use, hydraulic torque wrenches are the device of choice for applying torque to fasteners. Because the hydraulic wrench can be applied directly to the nut, it is easy to use. The hydraulic wrench is also the most powerful of the three. Hydraulic systems can deliver over 150,000 ft-lbs as needed.

Bolt Tensioner

Bolt tension is the tension of the bolt stud. You can use several different tools to tighten and loosen bolts. However, the only tool that can stretch a stud bolt is a hydraulic bolt tensioner. This tool allows you to achieve efficient and consistent bolt stretching.

If you need to stretch a bolt stud or shaft, a bolt tensioner is a tool to use. Bolt tensioners are usually found only as hydraulic power tools. In some cases, a tensioner is more useful and easier to use than a hydraulic torque wrench because of the bolt tensioner’s ability to apply a consistent tensile load on the bolt. For large bolted connections, the use of hydraulic bolt tensioners is the best way to ensure an even and accurate bolt load on the flange and to prevent accidental loosening over time.

Hydraulic Wrench Pumps and Hydraulic Tensioner Pumps

Strictly speaking, hydraulic wrench pumps and hydraulic tensioner pumps are not bolted tools, but they are the power source for hydraulic wrenches and bolt tensioners. You can choose a variety of hydraulic pumps to power hydraulic wrenches and bolt tensioners, such as pneumatic, electric, gasoline engines, etc., which can provide balanced and stable hydraulic power under different working conditions.


The main bolt tools used in the wind power industry are electric wrenches, hydraulic torque wrenches, and bolt tensioners. These three types of bolt tools can achieve the stability and safety of the entire bolt system. The easiest way to determine the best bolting tool for the job is to have a trusted manufacturer’s representative visit your site and investigate the application. Once complete, a system or combination of systems can be recommended for you to provide the highest level of efficiency and fastest return on investment.