A surgical instrument (500), comprising: a part (510) of the handle； a part (512) of the body that extends distally from the part of the handle and that defines a first longitudinal axis； a movable handle (516) arranged in the part of the handle and in mechanical cooperation with a drive member (272)； a set (17) of tools that includes an anvil (20), a set (18) of the cartridge and a contact surface, the set of tools being supported adjacent to a distal end of the body part； a drive beam (750, 802) that includes a plurality of layers (750a-750e), at least one layer having a proximal application part disposed adjacent to a proximal end thereof and which is configured to be applied on a part of the member discharge (272)； a closure apparatus (800) disposed adjacent to a distal end of the drive beam, the closure apparatus including a cutting surface (766, 808) therein, a straight section of the closure apparatus is generally I-shaped with parts horizontal, said horizontal parts being configured to be applied on the contact surface of the tool assembly (17), whereby at least a partial actuation of the movable handle moves the closure apparatus distally until application with the contact surface to approximate the anvil (20) and cartridge assembly (18)； and including the drive beam (750, 802) between four layers and six layers, at least one layer of the stainless steel drive beam being made, where each of the plurality of layers (750a-750e) of the beam of The drive includes at least one cut (770) disposed through, the drive beam being part of a disposable loading unit, and characterized in that parts of the closing apparatus (800) comprise a plastic surface provided by a plastic coating, overmoulded plastic or plastic covers (804) that at least partially cover said horizontal parts (806).Un instrumento quirúrgico (500), que comprende: una parte (510) de la empuñadura； una parte (512) del cuerpo que se extiende distalmente desde la parte de la empuñadura y que define un pr
