Transfer systems for interlinking are used for automatic transport between individual process stations within a transfer system. Transfer interlinking systems are special conveyor systems in which the workpieces are transported on workpiece carriers and fixed with workpiece holders. Transfer systems thus enable the orderly provision of the workpieces, exact positioning and the application of force in the process stations. A basic distinction is made between rigid and loose interlinking. 
With rigid interlinking, products are passed from station to station on workpiece carriers in a fixed cycle. These include rotary indexing tables and longitudinal indexing systems with a rigid cycle. 
In workpiece carrier transfer systems with loose linking, the connection between the forward drive of the conveyor line and the workpiece carrier is established by static friction. The workpiece carriers have free circulation and can be accumulated. 
Fast-feed longitudinal transfer systems allow a mixed form with rigid interlinking within the processing stations and with free circulation between the stations. 
Furthermore, robots of different designs can be used as interlinking means between processing stations.

With rigid interlinking, all workpiece carriers are coupled at fixed intervals, are guided in a closed circuit and are driven centrally. Therefore, all workpiece carriers are moved on synchronously in time. Rigid interlinking enables high cycle speeds and exact positioning in the machining stations with direct force application, but does not allow flexibility with regard to the material flow. Any malfunction causes the complete interlinked line to come to a standstill.

With loose linking, there is no fixed mechanical coupling of the workpiece carriers to the conveyor line, which is driven continuously or in a controlled manner. Conveying takes place by friction locking on conveyor belts, belts or plastic chains. In the process stations, the workpiece carriers usually have to be stopped, indexed and, in some stations, lifted out to allow force application without damaging the conveyor. Loose linking enables free circulation with high material flow flexibility as well as the infeed and outfeed of workpiece carriers. The transport of the workpieces between the process stations is independent of the cycle time. The workpiece carriers can be accumulated, which means that disruptions are only delayed or, in the case of short disruptions, do not affect the entire line at all.