The connection
determines the tool.

1. What torque is required?

The specification for your bolted joint is authoritative. Loosening may require a higher torque than the original tightening torque. Please therefore describe your task and operating conditions.

2. Square drive or cassette?

Square-drive torque wrenches use a suitable impact socket. Low-profile hydraulic torque wrenches engage directly with the nut and are suitable for restricted clearance and protruding threaded studs.

3. Which across-flats size and cassette group?

The cassette group must be taken into account for all TX and TXU models. Larger cassettes may have a different effective lever arm. Each range of across-flats sizes therefore has its own pressure–torque charts. The model name alone is insufficient to determine the applicable torque.

4. How much space is actually available?

Check the available space along the bolt axis and around the sides of the nut. Also consider tool length, reaction support, hoses and connections. For a square-drive torque wrench, include the fitted socket.

The terms “height”, “width” and “length” are only unambiguous when used with the relevant manufacturer’s drawing. The radius dimension in the TX/TXU catalogue does not automatically represent the full outside radius from the bolt centre.