Our Thunderbolt™ branded hexagon head anchors are an all-metal self-tapping anchor, cutting its own thread into the substrate; this results in no expansion stress, meaning that they are ideal for close to edge applications. They are quick and easy to use. Suitable for solid concrete, hollow concrete, most natural stone, brick, and block. Removable. CE approved. Available in either zinc and yellow, or galvanised, offering protection against corrosion.