An improved fastener for attaching metal to wood is described. The fastener is particularly suited for use as a railroad spike for attaching a metal rail to a wooden tie. The improved spike is adapted for installation by either driving or screwing the spike into the tie. A plurality of flutes are adapted to engage with the tie, thereby preventing loosening of the spike. The spike may be used with or without a metal boss or fishplate to secure a metal rail to a wooden tie.