Patent ID: 7354354

Claim:
An article comprising a golf club shaft having a yield strength of at least 25 MPa comprising: (i) a fine grained metallic layer comprising Ni having a grain size in the range of 2 to 5,000 nm, a hardness between 200 VHN and 3,000 VHN, a thickness ranging from 30 microns to 5 cm, a modulus of resilience ranging from 0.25 to 25 MPa; the weight of said fine grained metallic layer ranging from 5% to 95% of the weight of said golf club shaft and wherein said fine-grained metallic layer covers at least part of an inner or outer surface of the article, (ii) a polymer substrate having an average surface roughness of Ra 0.25 to 25 micron, (iii) a conductive metallic layer which is made of Ni or Ag and which is substantially thinner than (i); and said article having a torsional stiffness per unit weight improved by at least 5% when compared to the torsional stiffness per unit weight of an article the same but not containing (i).