In this study, metallic constantan (Cu55-Ni44-Mn1 wt %) alloy substrates were investigated as an alternate choice of substrates to grow carbon nanotubes (CNTs). No additional catalysts were used other than the as-rolled and annealed substrates to process CNTs on them. High density CNT growth was observed to take place on these substrates when suitable conditions were used in a thermal chemical vapor deposition (CVD) furnace with C2H2 as the carbon precursor. Scanning electron microscopy and transmission electron microscopy on these samples indicated the presence of several micron long CNTs ranging in 20- 100 nm in diameter. Raman spectra taken from the samples confirmed the presence of G band peaks (peak at similar to 1580 cm(-1)) and D band peaks (peak at similar to 1320 cm(-1)) commonly observed in CVD grown multiwall CNT samples with varying intensity ratios depending on the processing conditions. (C) 2008 American Vacuum Society.