A downhole tool releasing mechanism which includes a collet for releasably engaging a mandrel of a downhole tool. A retaining band is circumferentially disposed about the fingers of the collet for maintaining engagement of the collet and the mandrel prior to application of a predetermined axially directed force on the releasing mechanism. Upon application of such a force the collet fingers expand, breaking the shear band, the mandrel is released and the downhole tool is disengaged.