A cutting tool for thread cutting has a thread turning cutting insert releasably retained in an insert pocket by a fastening member. The thread turning cutting insert has a thread cutting portion having three spaced apart cutting teeth. and a chip forming groove recessed in an insert upper surface. The chip forming groove includes a near-flank groove surface close to the cutting teeth and far-flank grove surface further away from the cutting teeth. The thread cutting portion includes three cutting edges formed at the intersection of the insert upper surface and an insert peripheral surface. Each cutting edge is located on a respective cutting tooth. The thread cutting portion includes three planar land surfaces located on the insert upper surface. Each land surface extends from an entire length of a respective cutting edge to the near-flank groove surface.

There is provided a machining assembly and cutting insert for machining metal or like workpieces, wherein the cutting insert body has a cutting end. The cutting end comprises at least one cutting edge and at least one cutting lip formed adjacent the at least one cutting edge. The at least one cutting lip includes at least one cutting protrusion and associated chip cutting edge to split the chip formed by the at least one cutting edge, for producing chips during machining which are of a width that is sufficiently reduced to allow proper evacuation or removal.