The SDC Hi/Shear is a totally concealed, high security, failsafe locking mechanism with superior appearance. The patented Hi/Shear electromagnetic lock design incorporates a floating armature assembly and special alloy steel locking tabs on both the lock and armature assemblies, that may be adjusted both vertically and laterally to compensate for wide door gaps and warped or misaligned doors. Hi/Shear magnetic locks are ideal for use on commercial grade hollow metal and wood doors and frames and Herculite doors with top rails.