A method of manufacturing a matched pair of opposing jaw members of an end-effector assembly includes assembling a first jaw member having a knife channel, assembling a second jaw member having a knife channel, setting a jaw gap and aligning a first sealing plate of the first jaw member and a second sealing plate of the second jaw member in relation to one another by bringing the first jaw member and the second jaw member into clamped engagement with an alignment spacer. The alignment spacer is configured to engage the knife channel of the first jaw member and the knife channel of the second jaw member. The method also includes coupling the first jaw member to the second jaw member.