ITW Redhead Sleeve type anchors feature a split expansion sleeve over a threaded stud bolt body and integral expander, nut and washer. Anchors are made of Plated Carbon Steel, or Type 18-8 Stainless Steel. Redhead Sleeve Anchors" design allows them to anchor into concrete, brick and block. Sleeve anchors work by inserting them into a hole drilled into concrete. Turning the nut pulls the working end of the sleeve anchor up through the sleeve, expanding and anchoring itself securely in the concrete, brick or block. Anchors should be installed with carbide tipped hammer drill bits made in accordance to ANSI B212.15-1994. Anchors are tested to ASTM E488 criteria. Meets or exceeds U.S. Government G.S.A. specification A-A-55614 Type 2 ?(Formerly GSA: FF-S-325 Group VIII, Type 2), California State Fire Marshal, Factory Mutual and Underwriters Laboratories