The undercutting technique generates a positive-fit connection in concrete. This ensures top safety, even in the case of heavy cracking in concrete. The practically expansion-free installation of the anchor enables very low edge and axial clearances without splitting. For the various different applications, fischer offers the undercut anchor FSU, the ZYKON undercut anchor and the ZYKON hammerset anchor made from zinc-plated steel, stainless steel, and highly corrosion-resistant steel for pre-positioned and push-through installation and with an internal thread.