Dogs / metal pins for the fixation of workpieces during the throughfeed processing are among others used on double end tenoners and edge processing lines. They are part of the feeding chains / chain plates.

Dogs are used for the exact alignment of the workpiece during the workpiece infeed and for the precise guidance during workpiece processing (priority function) and thus for the warranty of exact squareness.

Usually, the dogs can be countersinked manually into the chain conveyor. This property is necessary for the lengthwise processing of long workpieces. Moreover the machine can be equipped for transversal processing: short distances between the dogs for transversal processing of narrow workpieces and larger distances between the dogs (via countersinking of the intervening dogs) for the lengthwise processing of wide workpieces.

If dogs can be countersinked and raised via machine control, one speaks of controlled dogs.