Abstract: A three piece stair nosing is used in new construction and the reconstruction and repair of stairs, primarily for industrial and commercial applications. The stair nosing comprises a metal sub-channel, a front channel including a tread surface, and a rear channel. The sub-channel includes one or more anchors to be embedded in uncured concrete which, when hardened, secures the sub-channel to the stair pan. The front channel includes a metal base and a tread bonded to the base to provide a skid resistant surface. The front channel is locked into place on top of the sub-channel with locking tabs and is secured to the sub-channel with fasteners after which the rear channel is press fit into place to complete the assembly.