Abstract: A graphite cast iron nitrided piston ring has a main body including matrix and a nitrided layer. The matrix is made of graphite cast iron, and the nitrided layer is formed by subjecting a surface of the matrix to contact a cylinder to a gas nitriding process. With the nitrided layer formed at the surface of the matrix made of graphite cast iron, the piston ring has sufficient hardness and good abrasion resistance.

Abstract: A graphite cast iron nitrided piston ring has a main body including matrix and a nitrided layer. The matrix is made of graphite cast iron, and the nitrided layer is formed by subjecting a surface of the matrix to contact a cylinder to a gas nitriding process. With the nitrided layer formed at the surface of the matrix made of graphite cast iron, the piston ring has sufficient hardness and good abrasion resistance.

Abstract: A new type of light comprises a casing used for containing an emitting device. Further, the emitting device comprises a couple of wires, an insulator ball, a filament and a fuse. The couple of wires are connected with a power supply via the casing, wherein the contact ponts of wires and casing are defined as the bottom of the light. Moreoever, the insulator is positioned above the bottom of the light. Subsequently, the filament is position above the insulator ball, and the fuse is posted on the top of wires. Particularly, the tops of the wires are wound to form hooks to hold the fuse. The hooks are flattened for increasing the adhesion of connection between the wires and the fuse.