Stem nut is one of the important parts of the valve drive. When the valve is working, the hand wheel or the electric device drives the valve stem nut mounted in the support box to rotate, and the valve stem nut transmits the movement and the opening / closing torque of the hand wheel or the electric device to the valve stem. The valve stem lifting valve sealing element , Valve, plunger, diaphragm, etc.), the valve opening and closing and sealing. Aluminum alloy stem nut with excellent mechanical properties and casting performance, high yield, small proportion, only about 1/3 of copper, the price is about 1/3 of copper, with higher specific strength (strength / Proportion) and price. The new deformed aluminum alloy developed by our university is a kind of aluminum alloy which has been refined by changing the shape and shape after pressing, bending, rolling and extruding, etc. The strength, hardness and compressive resistance Pulling has greatly improved, especially in the surface treatment process, the use of coating, drawing and other processes to enhance the surface hardness, scratch-resistant scratch. Deformed aluminum alloy stem nut material should have a certain strength, toughness and hardness, low coefficient of friction, good corrosion resistance and a certain degree of heat resistance. Suitable for handwheel and electric gate valve, globe valve, diaphragm valve and piston valve stem nut, but also can be widely used in the manufacture of bushings, bushings, worm gear crown and other wear parts, as a growing scarce copper Alloy materials, alternative products, with high economic and social benefits. Mechanical properties of the new deformation of aluminum alloy materials, so that the valve stem nut made at room temperature tensile strength σb 550Mpa, elongation δ of 12%, the surface hardness value should be HB ≥ 150, to meet the stem nut Requirements. The new deformation of the main material of the valve stem martensitic stainless steel, austenitic stainless steel and other friction properties, dry friction coefficient of less than 0.35.