Aluminium is a soft, durable, lightweight, malleable metal with appearance ranging from silvery to dull gray, depending on the surface roughness. Aluminium is nontoxic, nonmagnetic, and nonsparking. It is also insoluble in alcohol, though it can be soluble in water in certain forms. The yield strength of pure aluminium is 7¨C11 MPa, while aluminium alloys have yield strengths ranging from 200 MPa to 600 MPa. Aluminium has about one-third the density and stiffness of steel. It is ductile, and easily machined, cast, and extruded.That is also why people use aluminum sheet,aluminum tubes and aluminun extrusion for sign holder frames,picture frames,poster frames,inserts of slatwalls,slatwall accessories,slatwall brackets and aluminum tower displays etc.