Provided are a water-soluble metalworking oil agent (cutting oil agent or grinding oil agent) and a metalworking liquid, each of which has excellent cutting machining performance or grinding machining performance of aluminum or aluminum alloys, hardly causes rotting deterioration, and has excellent emulsion dispersion stability and stability of undiluted liquid, by containing specified components (A) to (E) as essential components without containing a machinability-improving agent with a high environmental load, such as chlorine, sulfur, and phosphorus. Provided is also a metalworking method using the same.

According to the present invention, the composition for treating aluminum containing surfaces comprises the reaction product of at least one amine-functionalized organosilane and/or oligomer and/or polymer thereof and at least one fatty acid, wherein the molar ratio of the amino group/s of the at least one amine-functionalized organosilane and/or oligomer and/or polymer thereof and of the at least one fatty acid is 1.2:1 to 1:2, and wherein the at least one amine-functionalized organosilane and/or oligomer and/or polymer thereof is linked to the at least one fatty acid by at least one carboxylic acid/amine salt bond and/or at least one amide bond.