Qhov kev sib koom ua ke ferrule muaj qhov zoo ntawm kev sib txuas ruaj ntseg, kev siv zog, kev ua haujlwm zoo, muaj kev nyab xeeb thiab txhim kho cov yeeb nkab ua haujlwm yog txhawm rau nkag cov yeeb nkab steel rau hauv ferrule , siv cov txiv ntoo ferrule kom xauv nws tiv thaiv cov ferrule, txiav rau hauv cov yeeb nkab thiab muab khi. Nws txuas nrog cov yeeb nkab steel yam tsis muaj vuam, uas yog qhov ua rau tiv thaiv kev tua hluav taws, thiab ua haujlwm ua haujlwm ua haujlwm tau tshwm sim los ntawm kev ua haujlwm vuam.
