Abstract: A pipe element has a circumferential shoulder at one end. The shoulder has an outer diameter greater than the outer diameter of the pipe element. A groove is positioned adjacent to the shoulder. The groove has a floor surface with an outer diameter less than the outer diameter of the pipe element. A bead is positioned contiguous with the groove. The bead has an apex with an outer diameter greater than the outer diameter of the pipe element. A combination of roller tools is used to cold work pipe elements and impart a desired shape to the sidewall in one method of manufacture. In another method, a spin forming tool is revolved in an orbit of increasing diameter within the pipe element captured within a die.

Abstract: A pipe element has a circumferential shoulder at one end. The shoulder has an outer diameter greater than the outer diameter of the pipe element. A groove is positioned adjacent to the shoulder. The groove has a floor surface with an outer diameter less than the outer diameter of the pipe element. A bead is positioned contiguous with the groove. The bead has an apex with an outer diameter greater than the outer diameter of the pipe element. A combination of roller tools is used to cold work pipe elements and impart a desired shape to the sidewall in one method of manufacture. In another method, a spin forming tool is revolved in an orbit of increasing diameter within the pipe element captured within a die.

Abstract: A pipe element has a circumferential shoulder at one end. The shoulder has an outer diameter greater than the outer diameter of the pipe element. A groove is positioned adjacent to the shoulder. The groove has a floor surface with an outer diameter less than the outer diameter of the pipe element. A bead is positioned contiguous with the groove. The bead has an apex with an outer diameter greater than the outer diameter of the pipe element. A combination of roller tools is used to cold work pipe elements and impart a desired shape to the sidewall in one method of manufacture. In another method, a spin forming tool is revolved in an orbit of increasing diameter within the pipe element captured within a die.

Abstract: A mechanical pipe coupling is formed of segments attached end to end to surround a central space. Each segment has arcuate keys which project toward the central space. Each key is formed of a pair of side surfaces and a mid surface between them. The mid surface is angularly oriented relative to a longitudinal axis perpendicular to a plane containing the segments. When used to couple pipe elements having grooves the angular orientation of the mid surfaces provides flexibility to the joint. A method of joining pipe elements end to end is also disclosed.