A cutting tool having a longitudinal axis defining forward and rearward directions, the cutting tool comprising: a cutting head comprising a cutting portion and a head clamping portion extending in a rearward direction from the cutting portion; a shank comprising a mounting portion for securing in a tool holder and a tool clamping portion extending in a forward direction from a forward end of the shank; the head clamping portion comprising a male or female coupling member (28, 26) and the tool clamping portion comprising a corresponding female or male coupling member (26, 28); the male coupling member comprising a circumferentially continuous peripheral surface having at least two longitudinally extending support surfaces with surface recesses extending between the support surfaces, wherein the support surfaces lie on the surface of a common first cylindrical surface having a first diameter D1; the female coupling member comprising a receiving bore having a circumferentially continuous bore wall comprising at least two longitudinally extending support walls with wall recesses extending between the support walls, wherein the support walls lie on the surface of a common third cylindrical surface having a third diameter D3, wherein D3<D1; the male coupling member being insertable into the female coupling member into a releasing position in which the support surfaces are located opposite the wall recesses, and being rotatable therefrom about the longitudinal axis into a locking position, characterized in that in the locking position the support surfaces abut the support walls, providing thereby self-clamping of the male and female coupling members wherein the male coupling member comprises a male torque transmission member and the female coupling member comprises a female torque transmission member. a cutting head comprising a cutting portion and a head clamping portion extending in a rearward direction from the cutting portion; a shank comprising a mounting portion for securing in a tool holder and a tool clamping portion extending in a forward direction from a forward end of the shank; the head clamping portion comprising a male or female coupling member (28, 26) and the tool clamping portion comprising a corresponding female or male coupling member (26, 28); the male coupling member comprising a circumferentially continuous peripheral surface having at least two longitudinally extending support surfaces with surface recesses extending between the support surfaces, wherein the support surfaces lie on the surface of a common first cylindrical surface having a first diameter D1; the female coupling member comprising a receiving bore having a circumferentially continuous bore wall comprising at least two longitudinally extending support walls with wall recesses extending between the support walls, wherein the support walls lie on the surface of a common third cylindrical surface having a third diameter D3, wherein D3<D1; the male coupling member being insertable into the female coupling member into a releasing position in which the support surfaces are located opposite the wall recesses, and being rotatable therefrom about the longitudinal axis into a locking position, characterized in that in the locking position the support surfaces abut the support walls, providing thereby self-clamping of the male and female coupling members wherein the male coupling member comprises a male torque transmission member and the female coupling member comprises a female torque transmission member.