Abstract: A saw chain includes a cutter link having a depth gauge with a rearwardly and upwardly sloping edge, and a guard link having a top edge generally paralleling the bottom of the kerf being cut by the saw chain. The guard link is further provided with a steep forward edge inclined upwardly and rearwardly toward the said top edge, and a rearward edge inclined upwardly and rearwardly wherein the rearward most portion of the guard link adjacent the following cutter link depth gauge is beneath a line extending between the top of the cutter link's cutting tooth and the peak of the depth gauge.

Abstract: A flat sheet metal plate defining a reference plane on one side. Said plate having first and second sections and an intermediate section. The first and second sections being flat and in a common plane, and the intermediate section formed into a semi-circular loop with a center portion of the loop removed. The remaining portions of the semi-circular loop provide a pair of guide lugs to guide a round file. The first and second sections are adapted to rest on the depth gauge and cutter of a cutting link in a saw chain with the guide lugs straddling the chain and aligned with the gullet of a cutting link to guide the file in a desired orientation against the cutting edge of the cutting link.

Abstract: A washer like metal blank formed into flutes. Each flute is shaped to receive the drive tangs of a saw chain so that successive drive tangs are alternately received in the flutes of first one side and then the other. The central opening is provided with keyways adapted to be mounted on a keyed hub.