1. Muaj zog txaus, rigidity, tsis tshua muaj huab cua, thiab lub teeb yuag yuav tsum tau ua kom muaj zog inertial tsawg.
2. Zoo thermal conductivity, tsis kam rau siab kub, siab siab, thiab corrosion, muaj peev xwm ua kom sov dissipation thiab me me rhuab cheeb tsam.
3. Cov coefficient tsawg ntawm kev sib txhuam yuav tsum muaj nyob nruab nrab ntawm lub piston thiab phab ntsa piston.
4. Kev hloov pauv me me ntawm qhov loj thiab cov duab nrog qhov hloov pauv kub yuav tsum tau ua, thiab kev tshem tawm tsawg kawg yuav tsum tau khaws cia ntawm lub piston thiab lub tog raj kheej phab ntsa.
5. Tsawg coefficient ntawm thermal expansion, tsis tshua muaj lub ntiajteb txawj nqus, thiab zoo anti-kev sib txhuam zog thiab thermal zog.
