Abstract: An automatic indexer a portable sheet bending brake having a first longitudinally extending member forming a clamp surface, a second longitudinally extending member movable with respect to the first member for clamping sheet material against the clamp surface, and a third member pivotally coupled to the second member for bending sheet material clamped between the first and second members over a bending anvil on the forward edge of the second member. The indexer includes a pair of slides having means for mounting the slides parallel to each other and spaced from each other lengthwise of the clamp surface on the bending brake. A pair of carriages are each slidably disposed on one of the slides, and a bar extends longitudinally between the carriages for engagement with an edge of sheet material inserted between the first and second members of the sheet bending brake.