A cutting tool holder, comprising: a cutting tool body having an insert pocket formed at a front end thereof for releasably receiving a cutting insert therein, an upper surface, and a sloping surface; and a top clamp releasably connected to the cutting tool body for securing a cutting insert in the insert pocket, wherein the top clamp comprises: a through-bore for receiving therein a securing member to secure the top clamp to the cutting tool body, the through-bore having a central axis; a bottom surface having a front portion, a first rear corner and a second rear corner; an inclined sliding surface formed at the first rear corner, for slidingly engaging the sloping surface of the tool body; a top engagement surface formed at the front portion, for engaging a top surface of a cutting insert; characterised by an insert-side engagement surface extending downwardly at the front portion, for engaging a peripheral surface of a cutting insert; and a supporting boss projecting downwardly from the second rear corner, for engaging the upper surface of the tool body and directing clamping forces to the front portion; wherein: an imaginary plane which extends through the top clamp, passes through the top engagement surface and includes the central axis of the through-bore, divides the top clamp such that the sliding surface is entirely located on one side of the imaginary plane, and the supporting boss and the top engagement surface are entirely located on an opposite side of the imaginary plane. a cutting tool body having an insert pocket formed at a front end thereof for releasably receiving a cutting insert therein, an upper surface, and a sloping surface; and a top clamp releasably connected to the cutting tool body for securing a cutting insert in the insert pocket, wherein the top clamp comprises: a through-bore for receiving therein a securing member to secure the top clamp to the cutting tool body, the through-bore having a central axis; a bottom surface having a front portion, a first rear corner and a second rear corner; an inclined sliding surface formed at the first rear corner, for slidingly engaging the sloping surface of the tool body; a top engagement surface formed at the front portion, for engaging a top surface of a cutting insert; characterised by an insert-side engagement surface extending downwardly at the front portion, for engaging a peripheral surface of a cutting insert; and a supporting boss projecting downwardly from the second rear corner, for engaging the upper surface of the tool body and directing clamping forces to the front portion; wherein: an imaginary plane which extends through the top clamp, passes through the top engagement surface and includes the central axis of the through-bore, divides the top clamp such that the sliding surface is entirely located on one side of the imaginary plane, and the supporting boss and the top engagement surface are entirely located on an opposite side of the imaginary plane. a through-bore for receiving therein a securing member to secure the top clamp to the cutting tool body, the through-bore having a central axis; a bottom surface having a front portion, a first rear corner and a second rear corner; an inclined sliding surface formed at the first rear corner, for slidingly engaging the sloping surface of the tool body; a top engagement surface formed at the front portion, for engaging a top surface of a cutting insert; characterised by an insert-side engagement surface extending downwardly at the front portion, for engaging a peripheral surface of a cutting insert; and a supporting boss projecting downwardly from the second rear corner, for engaging the upper surface of the tool body and directing clamping forces to the front portion; wherein: an imaginary plane which extends through the top clamp, passes through the top engagement surface and includes the central axis of the through-bore, divides the top clamp such that the sliding surface is entirely located on one side of the imaginary plane, and the supporting boss and the top engagement surface are entirely located on an opposite side of the imaginary plane. an imaginary plane which extends through the top clamp, passes through the top engagement surface and includes the central axis of the through-bore, divides the top clamp such that the sliding surface is entirely located on one side of the imaginary plane, and the supporting boss and the top engagement surface are entirely located on an opposite side of the imaginary plane.