Tractors are the paper-feed mechanism that pulls continuous-form paper through a dot-matrix or line printer: pull tractor units that grip the sprocket holes along the edge of fanfold paper and advance it evenly through the print path. Where a printer runs continuous multi-part forms rather than single sheets, the tractor is what keeps the feed consistent from the first page to the last.
Tractors are printer-model-specific - order by the exact printer, since mounting and sprocket spacing are matched to a particular model's feed path and do not interchange across printer families. Keep the tractor's sprocket pins and tension properly adjusted for the paper weight in use, since a misaligned tractor is a common cause of torn sprocket holes and paper jams. For sites still running legacy continuous-form printing, a spare tractor is worth stocking given how specialized these parts are to source. COLAMCO supplies printer tractors for the continuous-form printing operations business, government, and education organizations run.