1. Saib seb qhov saum npoo ntawm lub hose yas yog du, thiab saib seb lub cheeb ntawm lub hose yog cov qauv puag ncig, seb puas muaj npuas nyob rau hauv tag nrho cov yas hose lub cev, thiab seb cov phab ntsa thickness ntawm txhua feem yog uniform.
2. Hnov seb lub hose yas puas muaj ntxhiab tsw tshwj xeeb. Feem ntau, cov kav dej yas zoo yuav tsis tsim cov ntxhiab tsw thiab yuav tsis muaj ntxhiab tsw ntxhiab, tab sis cov kav dej tsis zoo yuav muaj qee qhov tsw.
3. Yog hais tias lub hose yas yog ua los ntawm cov khoom yas tsis zoo, nws yuav muaj hnub nyoog sai dua thaum lub sij hawm cia thiab siv, nws cov xim yuav daj, thiab cov yeeb nkab phab ntsa yuav harden. Qhov no tuaj yeem ua pov thawj los ntawm lub sijhawm. Cov yas zoo zoo hoses tseem tuaj yeem siv tau ib txwm siv thaum muab tawm hauv qhov qub cia.
