Dab tsi yog cov tsos mob ua ntej lub qhov cub nruab nrab zaus hnav?

1. Saib xyuas cov thickness faib ntawm phab ntsa sab hauv ntawm lub cub tawg, thiab tej zaum yuav nkag siab txog qhov yuav tsum tau perforated.

2. Tom qab nchuav tawm txhua lub cub tawg ntawm cov hlau molten, saib seb puas muaj cov cim dub ntawm phab ntsa sab hauv.

3. Siv cov xuab zeb thaj rau thaj tsam dub ua ntej siv.

4. Rau kev nyab xeeb, nres siv lub tshuab hluav taws xob nruab nrab yog tias koj tsis paub meej.