Expansion machine bolt anchors are available in different types such as double machine screw anchors which are a dual expansion die cast machine bolt mechanical anchor with internally expanding cone and can be used in concrete and some block, brick and stone based materials, single expansion anchors or single machine bolt or single machine screw anchors which have a pre-assembled expansion set of expansion shields and expander cone, and expansion screw anchors also known as Calk-in™ machine bolt anchors that are a internally threaded expander cone Zamac® alloy mechanical anchor with a malleable lead shield or sleeve which can be used in concrete, block, brick or stone.
