Countersunk Head Strike Anchors (aka the proprietary name Spike Anchor) is a single piece, tamper-proof, hammer in anchor for use in solid base materials such as concrete, brick, block, stone and other masonry. The S shaped kink in the Strike Anchor generates expansion forces once the anchor has been hammered into the pre-drilled hole. This anchor is a fast and economical way to fix steel brackets and timber structures to solid base materials. Strike Anchors are manufactured pre-expanded and simply require setting with a hammer, without the need for secondary tightening for installation, making it a common choice for fast installation applications. The countersunk head allows the anchor to be fixed discretely, and flush to the fixture surface.