Absolute pipe roughness for various materials

Material ε [mm]
asbestocement 0.15
cast iron asphalted 0.2
cast iron corroded 3
cast iron slightly corroded 1.5
cast iron new 1
concrete rough 3
concrete smooth 0.6
copper 0.05
galvanized steel 0.2
glass, plastics (PE, PP, PVC) 0.01
glazed stoneware 0.6
non-ferrous metals (drawn pipes) 0.05
precast concrete, joints sealed with mortar 0.6
rubber 0.03
seamless steel, new 0.2
steel heavily corroded 1
steel slightly corroded 0.3
steel zinced 0.2