Ny tampon’ny firaka aluminium dia manana sarimihetsika oksidena artifisialy, izay miloko mba hamoronana sarimihetsika mitambatra. Ny horonan-tsarimihetsika mitambatra dia tsy mahatohitra ny harafesina sy ny friction ihany, fa manana fanoherana afo ihany koa, ka natao ho varavarana afo firaka aluminium. Ny varavarana afo dia manana hery flexural avo sy deformation kely.