A collapsible staple driver (500, 500d, 500e, 500f, 500g, 500h, 500i) for use in a surgical staple cartridge, said collapsible staple driver (500, 500d, 500e, 500f, 500g, 500h, 500i) comprising: a base portion (502, 502f, 502g, 502h, 502i) configured to be operably supported by the surgical staple cartridge; a staple supporting portion (520, 520e, 520g, 520h, 520i) configured to be operably supported within the surgical staple cartridge adjacent to said base portion (502, 502f, 502g, 502h, 502i); and a resistive attachment structure (540, 540d, 540e, 580, 600, 620i, 640i) coacting with said base portion (502, 502f, 502g, 502h, 502i) and said staple supporting portion (520, 520e, 520g, 520h, 520i) to support said staple supporting portion (520, 520e, 520g, 520h, 520i) in a first position relative to said base portion (502, 502f, 502g, 502h, 502i) and configured to permit said staple supporting portion (520, 520e, 520g, 520h, 520i) to move toward said base portion (502, 502f, 502g, 502h, 502i) in response to compression forces applied to said staple supporting portion (520, 520e, 520g, 520h, 520i) and said base portion (502, 502f, 502g, 502h, 502i) during a staple firing operation, characterised in that: said resistive attachment structure (540, 540d, 540e, 580, 600, 620i, 640i) comprises at least one attachment member (540, 540d, 540e, 580, 600, 620i, 640i) protruding from one of the base portion (502, 502f, 502g, 502h, 502i) and the staple supporting portion (520, 520e, 520g, 520h, 520i) to be received in a corresponding aperture (542, 542e, 542f, 590, 610, 630i, 650i) in the other of the base portion (502, 502f, 502g, 502h, 502i) and the staple supporting portion (520, 520e, 520g, 520h, 520i), each attachment member and the corresponding aperture being configured relative to each other to establish a frictional fit therebetween that is overcome upon the application of the compression forces during the staple firing operation. a base portion (502, 502f, 502g, 502h, 502i) configured to be operably supported by the surgical staple cartridge; a staple supporting portion (520, 520e, 520g, 520h, 520i) configured to be operably supported within the surgical staple cartridge adjacent to said base portion (502, 502f, 502g, 502h, 502i); and a resistive attachment structure (540, 540d, 540e, 580, 600, 620i, 640i) coacting with said base portion (502, 502f, 502g, 502h, 502i) and said staple supporting portion (520, 520e, 520g, 520h, 520i) to support said staple supporting portion (520, 520e, 520g, 520h, 520i) in a first position relative to said base portion (502, 502f, 502g, 502h, 502i) and configured to permit said staple supporting portion (520, 520e, 520g, 520h, 520i) to move toward said base portion (502, 502f, 502g, 502h, 502i) in response to compression forces applied to said staple supporting portion (520, 520e, 520g, 520h, 520i) and said base portion (502, 502f, 502g, 502h, 502i) during a staple firing operation, characterised in that: said resistive attachment structure (540, 540d, 540e, 580, 600, 620i, 640i) comprises at least one attachment member (540, 540d, 540e, 580, 600, 620i, 640i) protruding from one of the base portion (502, 502f, 502g, 502h, 502i) and the staple supporting portion (520, 520e, 520g, 520h, 520i) to be received in a corresponding aperture (542, 542e, 542f, 590, 610, 630i, 650i) in the other of the base portion (502, 502f, 502g, 502h, 502i) and the staple supporting portion (520, 520e, 520g, 520h, 520i), each attachment member and the corresponding aperture being configured relative to each other to establish a frictional fit therebetween that is overcome upon the application of the compression forces during the staple firing operation. said resistive attachment structure (540, 540d, 540e, 580, 600, 620i, 640i) comprises at least one attachment member (540, 540d, 540e, 580, 600, 620i, 640i) protruding from one of the base portion (502, 502f, 502g, 502h, 502i) and the staple supporting portion (520, 520e, 520g, 520h, 520i) to be received in a corresponding aperture (542, 542e, 542f, 590, 610, 630i, 650i) in the other of the base portion (502, 502f, 502g, 502h, 502i) and the staple supporting portion (520, 520e, 520g, 520h, 520i), each attachment member and the corresponding aperture being configured relative to each other to establish a frictional fit therebetween that is overcome upon the application of the compression forces during the staple firing operation.