Qhov chaw saib xyuas kab ntsug (chain guide rail) yog ib qhov khoom siv los tshen, sau, thiab saib xyuas kab ntsug roj teeb lossis lwm yam kab ntsug siv rau kev sib cuag lossis muab tshuab mus rau qhov chaw xav tau. Qhov txheej txheem tseem ceeb tshaj plaws ntawm nws yog kom kab ntsug hlo tshaj, tso tsis pub kab ntsug hla siab (txh especially nyob rau qhov chaw ntev), kho cov kab ntsug thiab sprockets, thiab sau kab ntsug kom meej meej kom tsis txhob muaj kev pheej rau lwm tshuab. Cov kab ntsug no feem ntau tsim los ntawm cov khoom siv nyab, zoo li UHMW-PE (Ultra-High-Molecular-Weight Polyethylene), nylon, lossis cov hlau nyab nyab, thiab feem ntau muaj qhov muab dej ntxuav nrog nrog. Nyob rau hauv qhov kev tsim kho plastic, cov kab ntsug saib xyuas feem ntau pom tshwm nyob rau hauv qhov haul-off lossis puller units. Nyob rau hauv cov tshuab no, ib tug haul-off uas siv kab ntsug yuav siv ntau lub treads uas raug xaiv rau kab ntsug los nyob thiab muab daim duab extruded los ntawm qhov kho rau ib qhov laum uas raug sib xyaw nrog qhov output ntawm extruder. Cov kab ntsug saib xyuas nyob rau hauv qhov kev tshwm sim no yog tseem ceeb los kom kab ntsug thiab treads nyob hlo tshaj, thaub ib qhov laum zoo tib yam rau sab nraud kom tsis txhob muaj kev hloov pauv lossis kev slippage. Ib qhov kev phom kev nyab xeeb ntawm kab ntsug saib xyuas, xws li kev nyab xeeb loj heev uas cuam tshuam rau kev hlo tshaj, yuav tshwm sim kev muab tsis zoo, ua rau muaj kev hloov pauv rau qhov ntev ntawm daim duab, kev ntxuav sab nraud, lossis tib neeg tuaj yeem tshaj tawm qhov kev tshwm sim. Yog li, kev xaiv ib tug haul-off uas muaj cov kab ntsug saib xyuas nyab thiab zoo tshaj tshua yog tseem ceeb los kom tsim thoob ntawm qhov kev tsim kho tshuab tib leeg thiab kom paub tias qhov ntev tib yam ntawm cov khoom tiav.