Figure 1-12. Mechanically Expanded
Rivet Head and Stem Styles.
Mechanical Lock. Self-plugging mechanical lock rivets include the
3000-series CherryMAX and the 2000-series Cherrylock.
lock rivets may be substituted for solid-shank rivets when a solid-
shank rivet is inaccessible for bucking.
When substituting 3000-
series CherryMAX rivets for solid-shank rivets, the new rivet may be
the same diameter as the solid rivet it replaces. When substituting
2000-series Cherrylock rivets or bulbed Cherrylock rivets for solid-
shank rivets, the new rivet must be one diameter size larger than the
solid rivet it replaces. In 1979 the Army began replacing all self-
plugging rivets by attrition with the 3000-series CherryMAX rivet.
The change will reduce the inventory of installation tools and types
of rivets required in the Army supply system.
Cherrylock rivet is made in three parts: a hollow shank, a stem, and
a locking collar. The 3000-series CherryMAX rivet has an extra part
attached to the rivet stem:
the driving anvil (Figure 1-12a).
head styles of the shank are the same as those in solid-shank rivets.
The head also has a conical recess to accept the locking collar. The
stem has an extruded angle and land to expand the sleeve for hole
filling, a breakneck groove, a locking groove, and a head. The pull
grooves on the protruding end of the stem fit the jaws of the rivet
The mechanical lock between the stem and sleeve gives these
rivets approximately the same strength as common solid-shank rivets.