Abstract: The present invention relates to an attachment arrangement that comprises a body, an attachment component and a fastener. One of the body (20) and the attachment component defines a protrusion (22) and the other of the body (20) and the attachment component defines a recess configured to receive the protrusion (22). The fastener is operative to resist separation of the body (20) and the attachment component when the protrusion (22) is received in the recess. Each of the protrusion (22) and the recess defines a surface profile (28, 30) with the surface profiles cooperating with each other to force the body (20) and the attachment component progressively apart from each other against the operation of the fastener as the body (20) and the attachment component are rotated in relation to each other when the protrusion (22) is received in the recess.

Abstract: The present invention relates to hand held tool monitoring apparatus (10). The hand held tool monitoring apparatus (10) comprises a mount, which in use of the hand held tool monitoring apparatus forms part of a hand held tool (22), and a monitoring component (12) configured to be releasably attached to the mount. The monitoring component (12) comprises an operative part of the hand held tool monitoring apparatus (10) and the hand held tool monitoring apparatus further comprises a vibration sensor and a timer. The vibration sensor is operable to sense vibration of the hand held tool (22) and to provide a vibration signal in response to sensed vibration when the monitoring component is attached to the mount. The timer is operative in dependence on the vibration signal to record a duration of vibration of the hand held tool (22).