a plastic sprocket wheel includes a sprocket body having a series of circularly spaced recesses located around a body circumferential edge , there also being a body side face opening in at least one body side face which communicates with the recess edge openings so that replaceable tooth elements can be slidably inserted into an associated recess when tooth replacement such as required when one or more teeth of an operating sprocket break or are rendered unusable . the replacement mounting requires no separate fastening devices for holding replacement teeth securely to the sprocket body , friction fit being sufficient to that end . the sprocket body is of resilient material such as an acetal , a polyethylene , a polypropylene etc ., and the tooth elements can be of metal or the same material as the sprocket body , or such can be a combination of materials , e . g ., a strong metal tooth piece molded in a resilient or plastic material core . further forms of tooth element / sprocket body constructions are provided for use in and to counter effects in conveyors where right and / or left turn belt runs apply significant laterally directed force to the sprocket tooth elements .