A tilt anvil assembly for use with a surgical instrument, the tilt anvil assembly comprising a center rod, a head assembly, and a torsion spring configured to pivot the head assembly between a non-tilted position and a fully tilted position relative to the center rod, wherein the head assembly comprises a housing, a locking collar, and an anvil plate comprising staple deforming pockets and wherein the locking collar has a locked position preventing pivotal movement of the head assembly and an unlocked position allowing pivotal movement of the head assembly.
