There are several grades of both Gunmetal and Phospher bronze. One typical gunmetal contains, Cu85 Sn5 Zn5 Pb5: and a typical bronze contains, 89% Copper, 10.5% Tin and >0.5% phosphorous, although in both cases, there are many variations. A summary of the uses: Phosphor bronze Pb1, Pb2, Pb3 Generally used for bearings, gear wheels, springs and general coppersmithing. Leaded phosphor bronze Lpb1 This being a leaded phosphor bronze it is suitable for a wide range of bearings. It can also be used for valves, high-pressure steam fittings, general duty bushes. Gunmetal G1 A composition with good resistance to corrosion, which is also standard admiralty gunmetal. It can be used for high load, low speed bearings, high-pressure pipefittings, and also a certain amount of hydraulic castings. Leaded Gunmetal LG2 A material with excellent machining characteristics, good casting qualities and moderate strength. Particularly suitable where pressure tightness is required. Leaded Gunmetal LG4 When cast is not so sensitive to changes in section as LG2 and is also suitable where thick wall sections are incorporated. Is often used for high-pressure valves where liquid oxygen and nitrogen are present. Hydraulic pressure and centrifugal pump castings. Aluminium Bronze AB2 Has excellent bio fouling resistance and corrosion resistance. Used for acid resisting pump parts and marine use. As an aside, the lead in leaded bronze/gunmetal appears to have no effect upon silver soldering the material in question. Alan Stepney http://www.alanstepney.info Model Engineering & steam engine information pages MODEL ENGINEERING DISCUSSION LIST. To UNSUBSCRIBE from this list, send a blank email to, modeleng-request@xxxxxxxxxxxxx with the word "unsubscribe" in the subject line.