A relatively new product in the market, the large diameter concrete screw goes by many different names: LDT (Large Diameter Tapcon), wedge bolt (not to be confused with the wedge anchor), Screw Bolt, Titen HD or THD Anchor, Power Skru, and screw anchor, are just a few of the generic and brand names used for this product.

The variety of names are mostly a result of the many manufacturers that make them, but all of these names refer to a large (3/8” to ¾” diameter) concrete screw with a hex head (some sizes are also offered in a flat head), available in galvanized, stainless, or most commonly, zinc.