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I wanna prefer aluminum metal that is immune to fire and water.
No, no. Aluminum has a melting point of approximately 660°C. That's well below the temperature of a candle flame, which is approximately 1,100 °C.
Even burning wood reaches temperatures above 1,000°C, so your backup method is definitely not immune to fire. As o_e_l_e_o said, stainless steel is the best way to go.