Copper gaw hka lim ai shara ni hta grai kaja ai n-gun rawng ai raitim, n-gun ja ai-katsi ai shara (sh) sulfur{1}}law ai gas shara ni hta patina byin wa chye ai majaw, matut mahkai ai lam hpe ninghkap lu ai atsam grau law wa ai. Aluminium a ntsa gaw, n-gun ja ai oxide film byin wa chye ai majaw, de a malai, grau nna n-gun n rawng mat hkra pat shingdang lu ai. Raitim, oxide film (10−6Ω·cm2 daram) a hkam sharang ai atsam gaw, magri n-gun (10−6Ω·cm2) hta grau law ai majaw, tin shingnip, nickel shingnip (sh) anodic oxidation tsi lajang ai lam hku nna grau kaja hkra galaw ra ai.
Wan n-gun hpe nbung laru a n-gun atsam hte seng nna, magri a nbung laru hpe ninghkap lu ai atsam (0.0043/℃) gaw, aluminum (0.0041/℃) hta yawm ai, raitim, aluminium a nbung laru jat wa lu ai atsam (23.6×10−6/℃) gaw 14 lang daram rai nga ai. (16.5×10−6/℃). Katsi majan galai shai ai lam grai law ai masa ni hta, aluminum bar ni a thermal expansion hte contraction grau dan dawng ai majaw, matut mahkai ai shara ni hta n-gun yawm mat chye ai. Ndai hpe structure design hku nna (expansion gap ni hpe tawn da ai zawn re ai) shing nrai, n-gun rawng ai matut mahkai lam ni hpe lang nna shayawm kau mai ai.