Yuav kom paub qhov tuab ntawm phab ntsa ntawm 3/16 raj, peb yuav tsum paub qhov ntev ntawm sab nraud (OD) thiab sab hauv (ID) ntawm lub raj. Yog tias qhov ntev ntawm sab nraud yog 3/16″ thiab tsis muaj cov ntaub ntawv tshwj xeeb txog qhov ntev ntawm sab hauv, peb tsis tuaj yeem xam qhov tuab ntawm phab ntsa kom raug. Qhov tuab ntawm phab ntsa tuaj yeem sib txawv nyob ntawm hom raj thiab cov qauv tsim khoom tshwj xeeb.