1. Cov yam ntxwv nominal uas tau tshaj tawm hauv no yog cov yam ntxwv ntawm cov khoom, tab sis tsis qhia txog qhov sib txawv ntawm kev sim ib txwm muaj thiab yog li ntawd yuav tsum tsis txhob siv rau cov hom phiaj tshwj xeeb. Cov nqi raug suav ua puag ncig.
2. Cov khoom siv lub cev tau txiav txim siab rau ntawm cov qauv pwm uas tau npaj raws li Txheej Txheem C ntawm ASTM D4703, Annex A1.
3. Raws li zaj duab xis 0.025 mm uas tsim tawm ntawm qhov sib piv ntawm 4:1.