A support rail for a table top chain abraded powder or similar substances which intervene between top plates and support rails of a table top chain. A support rail is secured to a conveyor frame by means of threaded screws so as to support both sides at the lower surface of a top plate of a table top chain. The support rail has a plurality of circular concave recesses formed on the sliding surface relative to the top plate in a zigzag pattern for trapping obstacles such as abraded powder, liquid or lubricant on the sliding surface. The concave recess does not penetrate through the surface to the rear face, but serves to accumulate the abraded powder or similar therein.