A terminal sealed portion is formed on an end portion of a hollow rod made of steel. An enclosed space is formed on an inner side of the hollow rod. At an end of the enclosed space, a terminal gap is formed. A volatile powdered rust inhibitor is supplied in the enclosed space. As the volatile powdered rust inhibitor is vaporized, the enclosed space is turned into a rust-inhibiting atmosphere. As the vaporized component of the volatile powdered rust inhibitor is adsorbed to an inner surface of the enclosed space, an inner surface rust-inhibiting film is formed. The vaporized component also enters inside the terminal gap, and forms a terminal rust-inhibiting film.

On an end portion of a hollow rod, which is a material of a hollow coil spring, a terminal sealed portion is formed. The terminal sealed portion has a rotationally symmetric shape in which an axis passing through the center of the rod is a symmetric axis. The terminal sealed portion includes an end wall portion, and a distal-end-center closure portion formed on the axis. In the distal-end-center closure portion, a distal end opening portion of the spin-formed rod is joined together and formed as an integral part. On the axis at the inner surface of the end wall portion, a recess having a rotationally symmetric shape in which the axis is the symmetric axis is formed. A thickness of the recess of the end wall portion is reduced toward the axis.

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.

A paint spraying apparatus includes a supporting structure, a lower nozzle unit, and an upper nozzle unit. The lower nozzle unit includes lower flexible tubes and nozzles, and ejects powder paint toward an eye portion on a lower side of a stabilizer. The upper nozzle unit includes a first frame and a second frame. First flexible tubes are arranged on the first frame. Second flexible tubes are arranged on the second frame. The upper nozzles eject the powder paint toward an eye portion on an upper side of the stabilizer.

A control arm for the rear wheel suspension of a car where the control arm includes a cup-shaped spring mount with branches projecting from the spring seat. The branches may be designed as closed channels or U-shaped channels. In the upper part of the control arm there are flanges projecting from each side thereof. The flanges include a reinforced area around the spring seat. The cup-shaped spring seat is reinforces with wedges on the inside thereof. The spring seat and branches form a stiff frame structure. Also described is a method for manufacturing the control arm by forging.

A control arm for the rear wheel suspension of a car where the control arm includes a cup-shaped spring mount with branches projecting from the spring seat. The branches may be designed as closed channels or U-shaped channels. In the upper part of the control arm there are flanges projecting from each side thereof. The flanges include a reinforced area around the spring seat. The cup-shaped spring seat is reinforces with wedges on the inside thereof. The spring seat and branches form a stiff frame structure. Also described is a method for manufacturing the control arm by forging.