Roll grooved pipe fittings useful in the assembly of a variety of mechanically joined piping systems. These pipe fittings are roll grooved so that they can be mechanically joined directly with other like pipe fittings and/or with roll grooved straight pipe thereby substantially simplifying assembly. In addition, hybrid pipe fittings and systems are also disclosed. Methods and apparatus for manufacturing these aforementioned roll grooved pipe fittings are also disclosed and address both the roll grooving process itself, as well as various methodology and apparatus for correcting deformations that can occur as a result of the roll grooving process. Methods for using the aforementioned apparatus are also disclosed.

A helical pier and extension shaft, one end of which is formed with a thickened hexagonally shaped female end coupler using a hot forging process that swedges and compresses the walls of the female coupler into a thickened hexagonal configuration, with subsequent heat treatment to recover and enhance yield and tensile strength to the entire main body section and female end coupler of the helical pier and extension shafts. A corresponding hexagonally shaped male coupler may be milled and inertia friction welded to the opposite end of each extension shaft, or alternatively hot forged and internally upset as an integral homogeneous part of each extension shaft, thereby completing construction of the extension shaft with opposing corresponding male and female hexagonal couplers. The forgoing helical pier has particular benefits in applications requiring deep soil penetration and/or when using a grouted helical pier system.

A method of manufacturing an outer joint member of a constant velocity universal includes forming cup and shaft members of medium carbon steel, preparing, as the cup member, a cup member having cylindrical and bottom portions integrally formed by forging, and a joining end surface formed on an outer surface of the bottom portion after the forging, preparing, as the shaft member, a shaft member having a joining end surface to be joined to the bottom portion of the cup member, and bringing the joining end surfaces of the cup and shaft members into abutment against each other. The method also includes welding the cup and shaft members from an outer side of the cup member to an abutment portion between the cup and shaft members in a radial direction of the cup member.

A method of manufacturing an outer joint member of a constant velocity universal includes forming cup and shaft members of medium carbon steel, preparing, as the cup member, a cup member having cylindrical and bottom portions integrally formed by forging, and a joining end surface formed on an outer surface of the bottom portion after the forging, preparing, as the shaft member, a shaft member having a joining end surface to be joined to the bottom portion of the cup member, and bringing the joining end surfaces of the cup and shaft members into abutment against each other. The method also includes welding the cup and shaft members from an outer side of the cup member to an abutment portion between the cup and shaft members in a radial direction of the cup member.

The present invention provides a coupler comprising: an inner insertion part including a through-hole; and an outer support part for encompassing the outside of the inner insertion part, wherein the inner insertion part includes a connection groove through which the outer support part passes, the outer support part includes at least one projection part protruding in the center direction of the through-hole, and the projection part includes a groove part.

The present invention provides a coupler comprising: an inner insertion part including a through-hole; and an outer support part for encompassing the outside of the inner insertion part, wherein the inner insertion part includes a connection groove through which the outer support part passes, the outer support part includes at least one projection part protruding in the center direction of the through-hole, and the projection part includes a groove part.

Roll grooved pipe fittings useful in the assembly of a variety of mechanically joined piping systems. These pipe fittings are roll grooved so that they can be mechanically joined directly with other like pipe fittings and/or with roll grooved straight pipe thereby substantially simplifying assembly. In addition, the present disclosure also includes hybrid pipe fittings and systems. Methods and apparatus for manufacturing these aforementioned roll grooved pipe fittings address both the roll grooving process itself, as well as various methodology and apparatus for correcting deformations that can occur as a result of the roll grooving process. The present disclosure also includes methods for using the aforementioned apparatus.

A helical pier and extension shaft, one end of which is formed with a thickened hexagonally shaped female end coupler using a hot forging process that swedges and compresses the walls of the female coupler into a thickened hexagonal configuration, with subsequent heat treatment to recover and enhance yield and tensile strength to the entire main body section and female end coupler of the helical pier and extension shafts. A corresponding hexagonally shaped male coupler may be milled and inertia friction welded to the opposite end of each extension shaft, or alternatively hot forged and internally upset as an integral homogeneous part of each extension shaft, thereby completing construction of the extension shaft with opposing corresponding male and female hexagonal couplers. The forgoing helical pier has particular benefits in applications requiring deep soil penetration and/or when using a grouted helical pier system.

A cup member has a cylindrical portion, a bottom portion, and a short shaft portion having a solid shaft shape and including a joining end surface at an end portion thereof. A shaft member has a solid shaft shape and includes a joining end surface at one end thereof. The joining end surfaces of the cup and shaft members are brought into abutment against each other and welded from a radially outer side to form a welded portion. At this time, center segregation is prevented from interfering with the welded portion. The cup member is formed by forging including upsetting a billet having a columnar shape successively in a plurality of stages, extruding the cylindrical portion and the short shaft portion, and ironing the cylindrical portion. In the course of the upsetting, a region of the billet corresponding to a bottom side of the cup member is narrowed.

A cup member has a cylindrical portion, a bottom portion, and a short shaft portion having a solid shaft shape and including a joining end surface at an end portion thereof. A shaft member has a solid shaft shape and includes a joining end surface at one end thereof. The joining end surfaces of the cup and shaft members are brought into abutment against each other and welded from a radially outer side to form a welded portion. At this time, center segregation is prevented from interfering with the welded portion. The cup member is formed by forging including upsetting a billet having a columnar shape successively in a plurality of stages, extruding the cylindrical portion and the short shaft portion, and ironing the cylindrical portion. In the course of the upsetting, a region of the billet corresponding to a bottom side of the cup member is narrowed.