A sickle apparatus employing an endless cutter mechanism is provided wherein its modular construction allows the size of the apparatus to be readily tailored to variously sized equipment. Traveling blades are attached to the hollow pin drive chain by fasteners extending through the hollow pins to facilitate repair with a minimum of downtime. The use of liner material prevents a pivoting or twisting of the chain to stabilize the traveling blades while minimizing wear and tear. A positive attack of the traveling blade relative the fixed blade provides for a positive cutting action.