Prismatic dislocation arrays produced by single glide

Slip lines on opposite faces of a crystal deformed in single glide do not match in detail because the glide surfaces are never perfectly flat. The dislocation distribution produced by slip on an imperfect glide surface is modelled in terms of arrays of prismatic primary dislocations, associated with secondary slip. Such arrays can be produced by cross-slip. The model has certain features which match those observed in crystals which work harden in three stages.