· Second stage work hardening in fcc crystals through Shockley partial dislocations reacting to form "Cottrell-Lomer" dislocations is illustrated.
· Unit dislocations on the {111} planes dissociate into Shockley partial dislocations.
· Two Shockley partials, one gliding on each {111} plane, react at the < 110 > intersection of these planes and form a Cottrell-Lomer dislocation.