Abstract: In an attachment structure for an annular metal seal, an annular metal seal includes a seal body configured such that at least one of outer corner portions thereof corresponding to an inner corner portion of the seal groove has a sharp ridge, and in a state where a positioning ring is held between an inner-side side surface of the seal groove and an inner-diameter-side side surface or an outer-diameter-side side surface of the seal body, the annular metal seal is fitted in the seal groove with the positioning ring abutted on at least a portion of the inner-side side surface of the seal groove and the sharp ridge of the seal body spaced from the inner corner portion of the seal groove, and the first member and the second member are fastened with each other, so that inner and an outer sides of the annular metal seal are sealed.

Abstract: The metal seal has a middle base portion 3 of which cross-sectional configuration is laterally long rectangular, a first main convex portion 1 and a first auxiliary convex portion 11, and a second main convex portion 2 and a second auxiliary convex portion 12 respectively disposed on both ends of long sides 3A of the middle base portion 3. Ridge lines of the convex portions 1, 11, 2, and 12 form common straight lines L10 and L20 continuous to short sides of the rectangular.

Abstract: The metal seal has a middle base portion 3 of which cross-sectional configuration is laterally long rectangular, a first main convex portion 1 and a first auxiliary convex portion 11, and a second main convex portion 2 and a second auxiliary convex portion 12 respectively disposed on both ends of long sides 3A of the middle base portion 3. Ridge lines of the convex portions 1, 11, 2, and 12 form common straight lines L10 and L20 continuous to short sides of the rectangular.