The martensitic low temperature phase can be deformed similar to pure Tin: it can be bent back and forth without strain hardening. Thus, the risk of breakage of a component made from martensitic NiTinol is significantly lower as for instance in stainless steel. And finally when heated into the austenitic phase, the alloy recovers its initial shape.

The metallurgical reason for the martensite deformability is the twinned structure of the low temperature phase: the twin boundaries can be moved without much force and without formation of dislocations, which can be considered as being the initiator of fracture.