Abstract: A torque unit for use as an accessory to a conventional socket spanner or other wrench-type tool has a body which can be mounted at a selected position along the tool handle and a member movable relative to the body through which a turning moment is applied by the user, the unit including resilient means, preferably adjustable, biasing said member in opposition to the turning moment and warning means giving a signal sensed by the user, conveniently a sudden displacment and noise, when the load transmitted by the resilient means exceeds a predetermined level in use, of which the following is a specification.