What it does
Currency Determination No. 3 of 1998 is a delegated-instrument specification under the Currency Act 1965. It is made by the Assistant Treasurer, Roderick Charles Kemp, pursuant to subsection 13A(1) of the Currency Act 1965, dated 12 March 1998 and commencing on 1 April 1998 (see instrument heading, signature block, cl 2). The instrument mechanically does three things.
First, it formally identifies itself as Currency Determination No. 3 of 1998 (cl 1) and states its commencement date (cl 2). Those are legal formalities that fix the instrument’s identity and operative date.
Second, and central, it prescribes the physical specifications for particular coins by reference to a Schedule. Clause 3 states that for coins having the denomination and standard composition specified in columns 1 and 2 of Part 1 of the Schedule, the Determination sets the standard weight, allowable variation from that weight, the dimensions (diameter and thickness) and the design (columns 3, 4 and 5 of Part 1). The Schedule (Part 1) contains multiple rows of specifications for $5 coins in different compositions and designs, and for a $100 gold coin. The Schedule therefore operates as the operative technical specification that any minting must meet in order to be a coin consistent with this Determination.
Third, the Determination includes an application limitation in clause 4: it expressly does not affect any other determination of the specifications of a coin. In practical terms that means this Determination is additive , it adds or updates specific coin specifications without displacing other currency determinations made under the Currency Act.
Mechanically, the Schedule supplies precise numeric tolerances and design codes. For example, one $5 composition (copper, zinc, aluminium, tin) is given a standard weight of 20.000 grams with allowable variation ±0.500 g, diameter 38.90 mm, thickness 2.65 mm, shape S1, edge E1, obverse O3 and reverse R70 (see Part 1). A different $5 in 99.9% silver is given standard weight 31.635 g ±0.500 g, diameter 40.60 mm, thickness 4.00 mm, shape S1, edge E5, obverse O4 and reverse R73. A $100 coin in 99.99% gold has standard weight 10.021 g ±0.020 g, diameter 25.10 mm, thickness 2.40 mm, shape S1, edge E1, obverse O4 and reverse R75. Part 2 of the Schedule decodes the S, E, O and R symbols into the physical shape, edge style and descriptive design features (for example O4 includes an effigy of the Queen and an inscription of the denomination; R70-R75 describe the Sydney 2000 Olympic-related reverse motifs).