This paper has been retracted, as requested by Chinese Physics Letters, because of its substantial replication of an earlier paper, 'Measurements of near-ultimate strength for multiwalled carbon nanotubes and irradiation-induced crosslinking improvements' by Peng B et al., which appeared in Nature Nanotechnology 3(2008)626.I alone, as the first author of the paper, was responsible for this misconduct. Therefore, I would like to express my deepest apology to Professor Horacio Espinosa whose name was included in the above referenced paper without his knowledge, and to both journals, Chinese Physics Letters and Nature Nanotechnology.