A method for manufacturing a ball pen tip, in which a spring for biasing a ball is assembled to the ball pen tip, includes punching the ball pen tip by a punch from a rear end of the ball pen tip along a central axis direction of the ball pen tip to form a plastic flow ridge formed by plastic flow upheaving radially inward from an inner peripheral wall surface of the ball pen tip to assemble the spring to the ball pen tip by the plastic flow ridge.

Disclosed is a cartridge case for various caliber ammunition that consists essentially of a powdered metal and/or powdered metal alloy that is formed into the cartridge case through an injection mold processing. Also disclosed is a method for forming a cartridge case, which may include use of Metal Injection Molding (“MIM”) processes to produce the cartridge case which retains a primer, propellant, and/or a bullet. The method can include metal injection molding an initial part, and also at least one of tapering and trimming the initial part to form the finished cartridge case. Further embodiments can include the use of Finite Element Method (FEM) analysis to develop an optimized MIM design.

Disclosed is a cartridge case for various caliber ammunition that consists essentially of a powdered metal and/or powdered metal alloy that is formed into the cartridge case through an injection mold processing. Also disclosed is a method for forming a cartridge case, which may include use of Metal Injection Molding (“MIM”) processes to produce the cartridge case which retains a primer, propellant, and/or a bullet. The method can include metal injection molding an initial part, and also at least one of tapering and trimming the initial part to form the finished cartridge case. Further embodiments can include the use of Finite Element Method (FEM) analysis to develop an optimized MIM design.

A method of manufacturing a hollow coil spring which is made of a hollow wire in which a terminal sealed portion is formed on an end portion of the wire. The terminal sealed portion has a rotationally symmetric shape in which an axis passing through the center of the wire is the symmetric axis. The hollow coil spring includes an end wall portion, and an end face arc-shaped curved surface. The end wall portion includes an end face perpendicular to the axis. A distal-end-center closure portion is formed on the axis at the center of the end wall portion. A spring seat includes a base member and a sheet member. An end turn portion of the hollow coil spring is in contact with the sheet member. The end face of the end turn portion is opposed to a stopper wall of the spring seat.

Disclosed is a cartridge case for various caliber ammunition that consists essentially of a powdered metal and/or powdered metal alloy that is formed into the cartridge case through an injection mold processing. Also disclosed is a method for forming a cartridge case, which may include use of Metal Injection Molding (“MIM”) processes to produce the cartridge case which retains a primer, propellant, and/or a bullet. The method can include metal injection molding an initial part, and also at least one of tapering and trimming the initial part to form the finished cartridge case. Further embodiments can include the use of Finite Element Method (FEM) analysis to develop an optimized MIM design.

A method of manufacturing a hollow coil spring which is made of a hollow wire in which a terminal sealed portion is formed on an end portion of the wire. The terminal sealed portion has a rotationally symmetric shape in which an axis passing through the center of the wire is the symmetric axis. The hollow coil spring includes an end wall portion, and an end face arc-shaped curved surface. The end wall portion includes an end face perpendicular to the axis. A distal-end-center closure portion is formed on the axis at the center of the end wall portion. A spring seat includes a base member and a sheet member. An end turn portion of the hollow coil spring is in contact with the sheet member. The end face of the end turn portion is opposed to a stopper wall of the spring seat.

Disclosed is a cartridge case for various caliber ammunition that can consist essentially of a powdered metal and/or powdered metal alloy(s) that is formed into the cartridge case through an injection mold processing. Also disclosed is a method for forming a cartridge case, which may include use of Metal Injection Molding (“MIM”) processes to produce the cartridge case which retains a primer, propellant, and/or a bullet. Also disclosed are embodiments related to a case telescoped cartridge that may include a cap and a body. The body can consist essentially of or consists entirely of a powdered metal and/or powdered metal alloy(s) that has been formed through MIM. The cap can comprise plastic that has been formed through plastic molding or comprise powdered metal and/or powdered metal alloy(s) that has been formed through MIM.

Disclosed is a cartridge case for various caliber ammunition that can consist essentially of a powdered metal and/or powdered metal alloy(s) that is formed into the cartridge case through an injection mold processing. Also disclosed is a method for forming a cartridge case, which may include use of Metal Injection Molding (“MIM”) processes to produce the cartridge case which retains a primer, propellant, and/or a bullet. Also disclosed are embodiments related to a case telescoped cartridge that may include a cap and a body. The body can consist essentially of or consists entirely of a powdered metal and/or powdered metal alloy(s) that has been formed through MIM. The cap can comprise plastic that has been formed through plastic molding or comprise powdered metal and/or powdered metal alloy(s) that has been formed through MIM.

A method for manufacturing a stabilizer, the stabilizer including a main body bar that is elastically deformable, and a pair of connecting plates that are separately connected to a pair of left and right suspension devices, the method including a forging step of forming the connecting pate by forging both end portions of a material tube, in which in the forging step, both end portions of the material tube are crushed in a radial direction to be formed into the connecting plate in a state where a sealing metal plate heated to a temperature equal to or higher than a melting point is disposed inside both end portions of the material tube heated to a temperature lower than the melting point.

A hollow coil spring is made of a hollow wire in which a terminal sealed portion is formed on an end portion of the wire. The terminal sealed portion has a rotationally symmetric shape in which an axis passing through the center of the wire is the symmetric axis. The hollow coil spring includes an end wall portion, and an end face arc-shaped curved surface. The end wall portion includes an end face perpendicular to the axis. A distal-end-center closure portion is formed on the axis at the center of the end wall portion. A spring seat includes a base member and a sheet member. An end turn portion of the hollow coil spring is in contact with the sheet member. The end face of the end turn portion is opposed to a stopper wall of the spring seat.