Hydraulic
A hydraulic torque wrench is designed to apply torque on to a fastener in confined spaces.
Hydraulic torque is applied to the nut either directly or in conjunction with an impact socket. Hydraulic torque wrenches apply a predetermined, controlled amount of torque to a properly lubricated fastener.
There are two types of hydraulic torque wrenches: square drive and low profile. Depending on the application, one or the other will be the best tool to use.
Today's tools offer benefits such as lighter weights, smaller nose radius dimensions for fitting into tight spaces, use of exotic alloys, actuation triggers on the tool itself, multi-position reaction members, 360° × 360° hose swivels, and the ability to run multiple tools simultaneously from a single power pack.