2. It is strictly forbidden to use cast iron or cast steel khawms. The buckle body can be forged with killed steel, and the shaft pin can be machined after forging from bar material.
3. Qhovkhawm yuav tsum tsis txhob tho lossis welded los kho. Tom qab lub cev siv thiab tus pin tus pin tau hloov pauv mus tas li, tsis muaj kev kho dua.
4. Thaum siv, xyuas lub cev thiab lub ntsia liaj qhov rooj, thiab zam qhov hnav hnyav, deformation thiab tawg tawg.
5. Thaum siv, kab rov tav yuav tsum tsis txhob muaj kev nruj, thiab tus pin ncej yuav tsum tau muab tso nrog tus pin kev nyab xeeb.
6. Tom qab tus ncej tus pin tau sib sau ua ke kom raug, qhov dav ntawm lub cev yuav tsum tsis txhob txo qis, thiab cov xov txuas tau zoo.
7. Kev sivkhawmsyuav tsum tsis pub tshaj qhov teev tseg kev nyab xeeb.
