A surgical stapling instrument comprising: an elongated channel configured to removably support a surgical staple cartridge; an anvil movably supported relative to said elongated channel; a cutting head comprising: a vertically extending portion including an upper end and a lower end and a tissue cutting portion oriented between said upper end and said lower end ; at least one bottom tab protruding from said lower end of said vertically extending portion and configured to movably engage a bottom portion of said elongated channel; at least one upper tab portion protruding from said upper end of said vertically extending portion and configured to engage a portion of said anvil; and a firing bar assembly operably coupled to said cutting head and operably interfacing with a firing system, the firing bar assembly comprising: an upper firing bar segment coupled to said upper end of said vertically extending portion of said cutting head; and a lower firing bar segment coupled to said lower end of said vertically extending portion of said cutting head, characterised in that said upper and lower firing bar segments are spaced from each other at their respective points of attachment to the vertically extending portion and remaining portions of said upper and lower firing bars are in contiguous orientation relative to each other. an elongated channel configured to removably support a surgical staple cartridge; an anvil movably supported relative to said elongated channel; a cutting head comprising: a vertically extending portion including an upper end and a lower end and a tissue cutting portion oriented between said upper end and said lower end ; at least one bottom tab protruding from said lower end of said vertically extending portion and configured to movably engage a bottom portion of said elongated channel; at least one upper tab portion protruding from said upper end of said vertically extending portion and configured to engage a portion of said anvil; and a firing bar assembly operably coupled to said cutting head and operably interfacing with a firing system, the firing bar assembly comprising: an upper firing bar segment coupled to said upper end of said vertically extending portion of said cutting head; and a lower firing bar segment coupled to said lower end of said vertically extending portion of said cutting head, a vertically extending portion including an upper end and a lower end and a tissue cutting portion oriented between said upper end and said lower end ; at least one bottom tab protruding from said lower end of said vertically extending portion and configured to movably engage a bottom portion of said elongated channel; at least one upper tab portion protruding from said upper end of said vertically extending portion and configured to engage a portion of said anvil; and a firing bar assembly operably coupled to said cutting head and operably interfacing with a firing system, the firing bar assembly comprising: an upper firing bar segment coupled to said upper end of said vertically extending portion of said cutting head; and a lower firing bar segment coupled to said lower end of said vertically extending portion of said cutting head, an upper firing bar segment coupled to said upper end of said vertically extending portion of said cutting head; and a lower firing bar segment coupled to said lower end of said vertically extending portion of said cutting head, characterised in that said upper and lower firing bar segments are spaced from each other at their respective points of attachment to the vertically extending portion and remaining portions of said upper and lower firing bars are in contiguous orientation relative to each other. <EOS>