A workpiece material is fed between rollers to bend the workpiece material while rolling, wherein the workpiece has a first thickness portion and a second thickness portion connected to each other with a setting angle of 90 degrees. The first thickness portion increases from an inner side toward an outer side, and a thickness on an outer peripheral side of the first thickness portion is M, and a thickness of a cross section of the second thickness portion is N. The workpiece material is rolled in such that at a completion of bending, a thickness of a cross section of a first thickness portion is m, an outer radius of the first thickness portion is R, an inner radius of the first thickness portion is r, and a thickness of a cross section of a second thickness portion is n, and M equals to m(R/r), and N equals to n(R/r).

A workpiece material is fed between rollers to bend the workpiece material while rolling, wherein the workpiece has a first thickness portion and a second thickness portion connected to each other with a setting angle of 90 degrees. The first thickness portion increases from an inner side toward an outer side, and a thickness on an outer peripheral side of the first thickness portion is M, and a thickness of a cross section of the second thickness portion is N. The workpiece material is rolled in such that at a completion of bending, a thickness of a cross section of a first thickness portion is m, an outer radius of the first thickness portion is R, an inner radius of the first thickness portion is r, and a thickness of a cross section of a second thickness portion is n, and M equals to m(R/r), and N equals to n(R/r).

A roll bender apparatus is disclosed for bending a work piece, the apparatus including a base, a bending roller rotatably disposed on the base, a first guide roller rotatably disposed on base. and a second guide roller rotatably disposed on the base. A first work piece guide assembly is movable about the first guide roller and a second work piece guide assembly movable about the second guide roller. The first and second work piece guide assemblies are oriented to receive the work piece, and the first and second work piece guide assemblies are configured to move about the first and second guide rollers respectively in response to the work piece being bent as the work piece is advanced between the bending roller and the first and second guide rollers.

A roll bender apparatus is disclosed for bending a work piece, the apparatus including a base, a bending roller rotatably disposed on the base, a first guide roller rotatably disposed on base. and a second guide roller rotatably disposed on the base. A first work piece guide assembly is movable about the first guide roller and a second work piece guide assembly movable about the second guide roller. The first and second work piece guide assemblies are oriented to receive the work piece, and the first and second work piece guide assemblies are configured to move about the first and second guide rollers respectively in response to the work piece being bent as the work piece is advanced between the bending roller and the first and second guide rollers.

A roll bender apparatus is disclosed for bending a work piece, the apparatus including a base, a bending roller rotatably disposed on the base, a first guide roller rotatably disposed on base. and a second guide roller rotatably disposed on the base. A first work piece guide assembly is movable about the first guide roller and a second work piece guide assembly movable about the second guide roller. The first and second work piece guide assemblies are oriented to receive the work piece, and the first and second work piece guide assemblies are configured to move about the first and second guide rollers respectively in response to the work piece being bent as the work piece is advanced between the bending roller and the first and second guide rollers.

A roll bender apparatus is disclosed for bending a work piece, the apparatus including a base, a bending roller rotatably disposed on the base, a first guide roller rotatably disposed on base. and a second guide roller rotatably disposed on the base. A first work piece guide assembly is movable about the first guide roller and a second work piece guide assembly movable about the second guide roller. The first and second work piece guide assemblies are oriented to receive the work piece, and the first and second work piece guide assemblies are configured to move about the first and second guide rollers respectively in response to the work piece being bent as the work piece is advanced between the bending roller and the first and second guide rollers.

A workpiece material is fed between rollers to bend the workpiece material while rolling, wherein the workpiece has a first thickness portion and a second thickness portion connected to each other with a setting angle of 90 degrees. The first thickness portion increases from an inner side toward an outer side, and a thickness on an outer peripheral side of the first thickness portion is M, and a thickness of a cross section of the second thickness portion is N. The workpiece material is rolled in such that at a completion of bending, a thickness of a cross section of a first thickness portion is m, an outer radius of the first thickness portion is R, an inner radius of the first thickness portion is r, and a thickness of a cross section of a second thickness portion is n, and M equals to m(R/r), and N equals to n(R/r).

A workpiece material is fed between rollers to bend the workpiece material while rolling, wherein the workpiece has a first thickness portion and a second thickness portion connected to each other with a setting angle of 90 degrees. The first thickness portion increases from an inner side toward an outer side, and a thickness on an outer peripheral side of the first thickness portion is M, and a thickness of a cross section of the second thickness portion is N. The workpiece material is rolled in such that at a completion of bending, a thickness of a cross section of a first thickness portion is m, an outer radius of the first thickness portion is R, an inner radius of the first thickness portion is r, and a thickness of a cross section of a second thickness portion is n, and M equals to m(R/r), and N equals to n(R/r).

An enclosed cross-section building frame member has two elongated, sheet metal elements that are connected together by diametrically opposed, double overlapped seams. The elements are generally L shaped and can be compactly stacked for shipping to a construction site. The seams are cross serrated to prevent longitudinal slippage. A portable seaming apparatus has an entry guide tube for assembly of the elements prior to seaming. The apparatus is adjustable for making different sizes of frame members.

An enclosed cross-section building frame member has two elongated, sheet metal elements that are connected together by diametrically opposed, double overlapped seams. The elements are generally L shaped and can be compactly stacked for shipping to a construction site. The seams are cross serrated to prevent longitudinal slippage. A portable seaming apparatus has an entry guide tube for assembly of the elements prior to seaming. The apparatus is adjustable for making different sizes of frame members.