A tappet, which may be a fuel pump actuator, includes a body that is a contiguous piece of case-hardened ferrous metal. The body has a cylinder-conforming bore-running surface and an anti-rotation guide feature that has been made by stamping to project outwardly from the bore-running surface. A cam follower is mounted to the body. The body has been case hardened by ferritic nitrocarburizing, but has not been distorted by heat treatment and has a malleable interior. A transverse web for the tappet may be fully hardened. Axle holes for the cam follower may be formed by stamping. The tappet is durable and provides superior alignment of the roller to a cam, which reduces friction and noise.