Rivets are a two-part fastener consisting of a shell and a headed stem (mandrel) assembled so the shell can be placed into the colour matched work to be fastened and are usually for guttering roofing shed and steel buildings How Rivets Work: The rivet is ‘set’ by drawing the stem through the shell which causes the body to expand/compress to distort and clamp the material securely. After the desired clamping force is achieved the stem breaks off at a predetermined position and is discarded. A small portion of the stem remains trapped in the bottom of the shell to ensure the clamping force is retained in the joint. Blind rivets are designed to clamp together specific thicknesses of material. If the grip range is less than it should be (the rivet is too long) excessive material will be left on the blind side and more pulls will be required to break-off the mandrel. If the grip range is too large (rivet is too short) insufficient material may be left on the blind side to secure the joint Material fixing to: As a general rule the shell material of the rivet should be the same as the material under the head ie if aluminium is fastened to steel use steel rivets. Part of the stem remains in the shell after setting. In the case of steel stems this part may rust an undesirable attribute in many circumstances. All material is advisory only and its use by anyone is entirely voluntary. Reliance on it for any purpose by anyone is at the sole risk of that person and Bolt and Nut Australia is not responsible for any loss claim or damages arising therefrom.