According to an embodiment of the present invention, a ductile stainless steel pipe is made from stainless steel having an austenitic matrix structure, contains copper components, has a delta ferrite matrix structure of 1% or less on the basis of a grain size area, has a set outer diameter so as to transport an air conditioner refrigerant, wherein refrigerant R410a is used, and has a minimum thickness determined on the basis of the saturation pressure of the refrigerant.
