(a) The castings shall be cast from metal melted or
refined in any suitable metallurgical plant other than
an iron ore smelting furnace.
The minimum test results required on test bars 1.2
in. in diameter shall be in accordance with the table
NOTE.-Grade 16.5, 14 and 12 iron correspond to 26,
22 and 18.73 kg/cm² (16, 14 and 12 tons) minimum
tensile strength respectively.
(b) On analysis, the sulphur and phosphorous
content shall not exceed the following percentages:-
(c) Minimum Manganese content shall be related to sulphur
content by the following formula:-
(% sulphur x 1.7) + 0.3=% Manganese.
Which must be shown to be satisfied by routine quality
control laboratory analysis. In any event the Manganese
shall not be less than 0.5% and shall be within the
Phosphorous content shall be kept as low as economically
possible but in no circumstances shall it exceed 1.0%.