Tubes of diameter <5mm of a nickelate cathode material of composition Nd1.95NiO4 were prepared by cold-isostatic pressing (CIP) and extrusion. These tubes are intended as cathode support structure for micro-tubular SOFCs at reduced working temperatures around 700°C. The characteristics of these tubes - porosity, pore size, geometric dimensions and surface roughness - were measured by various techniques such as mercury intrusion, SEM-Imaging and with an in-house built diffusion setup. Diffusion measurements yielded average pore sizes of 0.12 μm for CIP-ed tubes and 0.22 μm for extruded tubes. Estimation of the loss due to oxygen diffusion has shown that the wall thickness of CIP-ed tubes must be reduced prior to coating processes in order to limit oxygen concentration overpotential loss during operation.