An apparatus comprising: (a) a body; (b) a shaft extending distally from the body; and (c) a stapling head assembly positioned at a distal end of the shaft, wherein the stapling head assembly comprises: (i) a staple driver member configured to drive a plurality of staples into tissue, and (ii) a knife member configured to cut through the tissue, wherein the knife member comprises: a proximal end, a distal end, and a cylindrical body extending between the proximal and distal ends, wherein the cylindrical body includes at least one coupling feature that operatively couples the knife member with the staple driver member, wherein the stapling head assembly further comprises a connector that couples the knife member with the staple driver member, and wherein the connector includes a proximal end, a distal end, and a body disposed therebetween, wherein the proximal end of the connector includes a flat surface, wherein the staple driver member includes a flat surface, characterized in that the flat surfaces of the connector and the staple driver member are fixably coupled together. (a) a body; (b) a shaft extending distally from the body; and (c) a stapling head assembly positioned at a distal end of the shaft, wherein the stapling head assembly comprises: (i) a staple driver member configured to drive a plurality of staples into tissue, and (ii) a knife member configured to cut through the tissue, wherein the knife member comprises: a proximal end, a distal end, and a cylindrical body extending between the proximal and distal ends, wherein the cylindrical body includes at least one coupling feature that operatively couples the knife member with the staple driver member, wherein the stapling head assembly further comprises a connector that couples the knife member with the staple driver member, and wherein the connector includes a proximal end, a distal end, and a body disposed therebetween, wherein the proximal end of the connector includes a flat surface, wherein the staple driver member includes a flat surface, characterized in that the flat surfaces of the connector and the staple driver member are fixably coupled together. (i) a staple driver member configured to drive a plurality of staples into tissue, and (ii) a knife member configured to cut through the tissue, wherein the knife member comprises: a proximal end, a distal end, and a cylindrical body extending between the proximal and distal ends, wherein the cylindrical body includes at least one coupling feature that operatively couples the knife member with the staple driver member, a proximal end, a distal end, and a cylindrical body extending between the proximal and distal ends, wherein the cylindrical body includes at least one coupling feature that operatively couples the knife member with the staple driver member, wherein the stapling head assembly further comprises a connector that couples the knife member with the staple driver member, and wherein the connector includes a proximal end, a distal end, and a body disposed therebetween, wherein the proximal end of the connector includes a flat surface, wherein the staple driver member includes a flat surface, characterized in that the flat surfaces of the connector and the staple driver member are fixably coupled together.