RELIEF VALVE

PROBLEM TO BE SOLVED: To realize miniaturization of a relief valve without damaging the strength of the relief valve by providing a screw relief part at a male screw lower end part, extending the bottom part of a chamber to this screw relief part. SOLUTION: At a relief valve, a valve body 8 made up by being provided with an opening 6 that exists at the center of a lower surface and at the upper part of a valve seat 3 part in a metal body 1 and by being fitted with an elastic body packing 7 in the opening 6; a compression spring 9; and a plate 11 having a through-opening 10 at its center are housed in order, and by calking the upper part opening edge of the body 1 at the plate 11 upper edge, fixation is carried out, and screw relief pert 12a is provided at the lower end pert of a male screw 12, and a position of the bottom part of a chamber 4 is arranged so that it may be the same as the position of the relief part 12e upper end of the male screw 12 or may reach the lower part position.