An end effector for use with a surgical fastening instrument comprising a first jaw, a second jaw, and a firing member is disclosed. The firing member, in various embodiments, further includes a cutting surface, a first portion configured to engage the first jaw, and a second portion configured to engage the second jaw. The first portion can be comprised of a first material wherein the firing member can further include an insert engaged with the first portion comprised of an insert material which is different than the first material. In various instances, the first portion and the second portion are configured to co-operatively set a tissue gap distance between the first jaw and the second jaw.