Face grooving tool body for metal cutting

A face grooving tool body comprising a blade portion including a top surface and an opposite bottom surface, a first side surface and an opposite second side surface, a front end and an opposite rear end, a longitudinal axis of the blade portion coinciding with a primary cutting feed direction of the blade portion, an upper blade portion associated with the top surface and a lower blade portion associated with the bottom surface, wherein the upper and lower blade portions are separated by a slit extending from the front end to a rear slit end, the slit intersecting the first and second side surfaces, the slit including an insert seat for a grooving insert, wherein the insert seat opens in the front end, the insert seat including an upper clamping surface formed in the upper blade portion, an opposite lower support surface formed in the lower blade portion, and a rear support surface formed in the lower blade portion, wherein the lower support surface extends a greater distance from the rear end than a distance the upper clamping surface extends from the rear end, wherein the second side surface of the lower blade portion is curved around a second side surface axis of curvature extending parallel to the longitudinal axis, wherein a key hole is formed in the blade portion, the slit including a slit portion extending between a slit portion front end and a slit portion rear end, the slit portion being located between the rear slit end and the insert seat, wherein a distance from the bottom surface to rear slit end is greater than a distance from the bottom surface to the slit portion front end, the distances being measured in planes perpendicular to the longitudinal axis, and wherein the slit portion or at least 50% of a length of the slit portion has a shape of a concave function in a side view.