Through bolt anchors are designed for use in concrete or dense natural stone with a strength greater than 20N/mm2 and are probably the most widely used fixing bolt in todays market. The throughbolt requires a hole in concrete the same diameter as the bolt, thus allowing the hole to be drilled through the fixture avoiding lengthy marking out procedures. Throughbolts are a versatile, cost-effective anchor combining ease of installation with good load carrying capabilities. When selecting any fixing bolts the following factors must be considered. – Thickness of fixture including any packing. – Non-structural screed must be included in the fixture thickness. – Compressive strength of concrete. – Distance from any edge. – Centre to centre distance of anchors.