A device for forming circumferential grooves in pipe elements uses multiple geared cam bodies mounted on a carriage which rotates about a fixed pinion. The gears engage with the pinion which causes the geared cam bodies to rotate relative to the carriage. Traction surfaces and cam surfaces on the cam bodies traverse the outer surface of the pipe element and impress a circumferential groove therein. Each cam surface has a region of increasing radius and may have a region of constant radius. Second cam surfaces, positioned in spaced relation axially to the first cam surfaces, may also extend around the cam bodies. The second cam surfaces have a constant radius and limit flare of the pipe element.