Various grades of reinforcing rod such as ic used in building construction were
available but quality and strength characteristics varied widely from sample to sample.
One of the better rods available in this class was a 6 ma wire rod produced locally to
Japanese Standard Specification SS41. This steel gave, on test, a tensile strength of 8.9 kg/mm2 (14,000 psi), An imported hard drawn stool wire of 6 mm (1/4") diamotor
was also:available but only in short lengths and this, on test, gave a lower tensile
strength of 8,9 kg/mm2 (12,600 psi). Although hard drawn or high tensile steel rode
are more suitable from the point of view of less distortion and be-t fairing, both
the lower tensile strength and the short lengths, necessitating considerably moro
lapping of rode in the construction, excluded the imported hard drawn rod.
The choice of the 3S41 6 mm (1/4"). rod was largely dictated by local supplies, and
should high tensile, prestressing steel in the required diameters become readily
available then this would be a better choice in the future.