Abstract: A tappet, which may be a pump actuator, comprises a body that is a contiguous piece of ferrous metal. The body comprises an outer shell and an inner side. The outer shell is case-hardened to a first hardness, and the inner side comprises a second hardness less than the first hardness. The outer shell comprises a bore-running surface and an outward projection that is operative as an anti-rotation guide feature and projects outwardly from the bore-running surface. The body further comprises two parallel planar surfaces disposed at a drive-input end of the body and an axle hole defined in each of the two parallel planar surfaces. The tappet further comprises an axial support pin mounted through the axle hole of each of the two parallel planar surfaces and a cam follower mounted to the body via the axial support pin.

Abstract: 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.

Abstract: 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.