A surgical fastener applying apparatus comprising: a fastener assembly including an anvil section and a cartridge section, the cartridge section and the anvil section movable from an unclamped position to a clamped position to clamp tissue therebetween, the cartridge section having a plurality of retention slots; a plurality of first surgical fasteners and a plurality of second surgical fasteners, each surgical fastener disposed within a corresponding retention slot, the plurality of first surgical fasteners having a first backspan with a first configuration and the plurality of second surgical fasteners having a second backspan with a second configuration, wherein the first configuration is different than the second configuration, wherein the first configuration applies a first compressive force to tissue upon formation of the plurality of first surgical fasteners and the second configuration applies a second compressive force to tissue upon formation of the plurality of second surgical fasteners, the second compressive force being different than the first compressive force; wherein a formed configuration of the first and second surgical fasteners varies in that an interior space between the backspan and legs of the first surgical fasteners after formation is less than the interior space of the second surgical fasteners, such that the first compressive force is greater than the second compressive force, characterized in that, as the plurality of first surgical fasteners are formed, one or more of a plurality of first pushers disposed within the retention slots forms a first recess in the first backspan of one or more of the first surgical fasteners to define the formed first configuration, and as the plurality of second surgical fasteners are formed, a plurality of second pushers disposed within the retention slots forms a the second backspan of the second surgical fasteners to define the formed second configuration. a fastener assembly including an anvil section and a cartridge section, the cartridge section and the anvil section movable from an unclamped position to a clamped position to clamp tissue therebetween, the cartridge section having a plurality of retention slots; a plurality of first surgical fasteners and a plurality of second surgical fasteners, each surgical fastener disposed within a corresponding retention slot, the plurality of first surgical fasteners having a first backspan with a first configuration and the plurality of second surgical fasteners having a second backspan with a second configuration, wherein the first configuration is different than the second configuration, wherein the first configuration applies a first compressive force to tissue upon formation of the plurality of first surgical fasteners and the second configuration applies a second compressive force to tissue upon formation of the plurality of second surgical fasteners, the second compressive force being different than the first compressive force; wherein a formed configuration of the first and second surgical fasteners varies in that an interior space between the backspan and legs of the first surgical fasteners after formation is less than the interior space of the second surgical fasteners, such that the first compressive force is greater than the second compressive force, characterized in that, as the plurality of first surgical fasteners are formed, one or more of a plurality of first pushers disposed within the retention slots forms a first recess in the first backspan of one or more of the first surgical fasteners to define the formed first configuration, and as the plurality of second surgical fasteners are formed, a plurality of second pushers disposed within the retention slots forms a the second backspan of the second surgical fasteners to define the formed second configuration.