The 1931 Indian Penny With the Dropped 1 Reverse - Less than 1,000 Were Struck

“The constant aim of producing a "good" coin was usually brought closer by varying a process in an experimental way. Experimentation was a long tradition of The Royal Mint, London and its branches.[1]

The 1931 Dropped 1 Indian penny is widely agreed to be one of Australia’s rarest pennies, yet it is a coin that the average collector and the general public know little about - a reasonable level of numismatic knowledge is required to identify and appreciate it. 

This compelling coin shares a great deal of history with the glamour rarity that preceded it in 1930 - research unequivocally shows that both coins are the result of practical efforts by Melbourne Mint staff during downtime in the Great Depression aimed at improving productivity.

Each and every Australian penny dated 1931 shares the same basic designs - experienced collectors are well aware they can be classified as one of four varieties, depending on the position of certain design elements either side.1931 Dropped 1 Indian Penny

The 1931 Dropped 1 Indian penny is clearly the rarest of the four 1931 penny varieties, and although research has confirmed that it is directly linked to the 1930 penny, that relationship is not what many collectors have presumed it to be.

The Challenge of Mass Production - Extending Die Life

In his book titled "Australian Coinage - An Account of Particular Coins”, Mullett describes the problems that Melbourne Mint staff encountered in the production of pennies in the late 1920s: “By this time, problems were increasing in the penny production, and this is shown by a change of master tools in 1928.[2] 

Bill Mullett retired as a staff member of the Melbourne Mint in 1977. Mullett clearly had a deep interest in making the history of coin production in Australia accessible, as when he retired, he “was able to research at great length the records of the Melbourne Branch of the Royal Mint and those of the Sydney Branch which had been preserved in Melbourne.[3]

Regarding penny production in 1928, Mullett recounted that “In the following year, the problem became more obvious. The die life in 1928 ranged from 30,000 to 166,000, but in 1929 die life frequently was below 10,000, with the average for reverse dies being 46,000 and for obverse dies 34,000. Later in the year the cause of failure of the dies, recorded as cracking, was noted. 

With the deterioration of the hubs caused by sinking (and spreading), the effect would be to increase the pressure needed to bring up the impression on the coins so leading to an early failure of the dies by cracking. A letter from H.D. McCay in London dated 20.3.30 confirms this problem in that at some time previously he was asked for advice. His suggestions of the cause and ways in which the problems might be overcome are enlightening. The changes which had not been tried in Melbourne were then made.[4]

Mullett’s work is well-known to numismatists that are interested in the technical details behind the production of Australia’s Commonwealth coins, there are three reasons why it is far less well known outside that circle. 

Each of Mullett’s three books on Australia’s coins were self-published in very limited numbers. For that reason alone, Mullett’s work is not well known. Not only that, Mullett did not particularly interact with the Australian numismatic community - once his work was published, it was not disseminated widely. Lastly, Mullett’s writing style is extremely technical - he bases his explanation of the background to certain coins by recounting the manufacture and movement of the dies used to strike them. When the dates for each movement of a die are combined with the reference numbers allocated to them and the assorted technical terms used to label them, it is challenging to arrive at the consequences of what Mullett has recorded. The effort required is certainly worth it - Mullett’s work really is the only source of verifiable information on a number of Australia’s most important 20th-century coins.

Experimentation - A Fundamental Phase In Effective Manufacturing

Without specific reference to pennies in 1928, Mullett states that “The constant aim of producing a "good" coin was usually brought closer by varying a process in an experimental way. Experimentation was a long tradition of The Royal Mint, London and its branches.[5] 

Experimentation by Mint staff then should therefore not be seen as frivolous activity indulged in to while away a quiet day, but more as an essential phase of the experiential process that is effective manufacturing. Mullett clearly confirms that successful minting is achieved and maintained by learning on the job, by trial and by error.

It is not correct therefore to say that the Melbourne Mint staff began experimenting with adjustments to their established processes after the Great Depression started. Mullett’s research demonstrates that internal discussion within the Mint about what could be done to improve the life of their penny dies started as early as 1928 - at least a year before the Great Depression began, and earlier still than the formal advice from Treasury that no coins other than halfpennies would be required in 1930.

  It is fair to say however that a reduced workload in 1930 enabled Melbourne Mint staff to spend more time on this project than they otherwise would have. The total number of copper and silver coins struck for circulation across each of the three Australian mints in 1930 was just 581,800, as against 4,117,900 struck in 1929 - a drop of 86%.[6]

The Annual Report for the Melbourne Mint in 1930 included the following comment by the Deputy Master: “Owing to the lack of orders for token coinage...unestablished staff have been working short time during the year.[7] Repairs and upgrades to the machinery are also mentioned, however it is the experimentation that numismatists will be most interested in.

“An Excursion Through The Varieties Of Steel Available”

1930 and 1931 appear to have been a time for the Mint staff to run practical tests on penny dies that were produced by a range of suppliers. Different dies were tested on the production floor, the number of coins struck by them was recorded, the aim was to identify a supplier and die steel that optimised production. 

The different types of steel that were tested during this period included “No. 2” and “No. 3” steel; Huntsman's[8] forgings;  Armstrong's (forgings);[9] Dannemora steel[10]; Skellington steel;[11] BCS (Bohler Carbon Steel);[12] and MIC.

It is difficult to determine from Mullett’s research whether the experimentation performed during this period regularly included the variation of factors other than die steel. One process variation is noted by Mullett in 1929: “On 28.2.29 a 15' cone was tried on the steel blanks for pence and halfpence working dies (two pairs of pence) using a No. 3 steel.[13] Mullett states that “The reverses were good and the obverse recorded was fair…”[14]

The first thought we might have regarding “experimentation” and dies with different characteristics might be that different dies were intentionally used to facilitate measurement of the life those coins had in circulation. We know that the designs of certain pennies (those struck during 1919 and 1920 are just two examples) were altered very slightly to enable quality control if required, however that was not the case in this instance.

Melbourne Mint staff were focused on increasing productivity rather than measuring the longevity of the product those trials created, and the results of each test were known as soon as each production run was finished. At least two different obverse and reverse penny hubs were in use at that time, which is the reason there are four different varieties of the 1931 penny.

London, Calcutta and Birmingham

When the production of copper coins first took place on Australian soil, the working dies were supplied by the Royal Mint in London.[15] In 1920 however, as part of the gradual decentralisation of Australia’s coin production, the Melbourne Mint obtained penny master tools from Calcutta[16].

To the untrained eye, each of these different dies looks by and large exactly the same, and for all intents and purposes, they are. They can be differentiated in a number of ways, however perhaps most readily by the number of rim beads that are around the perimeter of the design. The shape of the “R” in “BRITT” also differs between each die. The table below lists the number of beads for each of the obverse and reverse die types used on Australian pennies during the King George V period (1911 ~ 1936):

Die Source












1931 Penny Types

Collectors need not worry about counting the number of rim beads on the coins they assess, as the different die types can be determined by checking how certain design elements line up with the denticles around the rim. The following table identifies how each of the different obverse and reverse die types are identified:

Die Source




The upstroke in the "N" of "OMN" falls between two denticles.

The tips of the letters “AL” in “AUSTRALIA” are each in line with a rim denticle, while the tips of the letters “IA” fall between two denticles



The tips of the letters “AL” in “AUSTRALIA” each fall between two denticles, while the tips of the letters “IA” are each in line with a rim denticle.


The upstroke in the "N" of "OMN" lines up with a denticle

The tip of the letter “L” in “AUSTRALIA” is in line with a rim denticle, while the tips of the letters “A” and “IA” fall between two denticles.

The research done by Mullett into the die records of the Melbourne Mint enables us to determine the exact dates on which each of the four 1931 penny varieties were struck.

Production Ranged From August 1931 Through to July 1932

The first 1931 pennies were struck on (or shortly after) August 13th, 1931. Mullett states that “At the end of the trials of the 1930 reverses, the obverse die A2B10 was used with a 1931 reverse for a production of 46,000.[17]” Working back from Mulllett’s comments on each die, hub and master die, it is possible to determine that these coins had the Indian obverse, and the standard reverse. On the 3rd, 10th and 11th of September 1931, a number of 1931 pennies with the London obverse and the Dropped 1 reverse were struck. Based on Mullett’s research, the current best estimate of the mintage for these coins is 279,000 coins.

The following comment indicates the date that the  1931 pennies with the Indian obverse and the Dropped 1 reverse were struck on September 11th 1931: “…the reverse S150 with obverse A2B16 107 was at the presses on 11.9.31 for nil thousand and cracking was the cause of failure.[18] 

The balance of the production of 1931 pennies was struck between September 15th 1931 and “about 9 July 1932”[19], and all appear to have had the London obverse and the standard reverse.

What of the Presumed Relationship Between the 1930 Penny and the 1931 Indian Pennies?

Many collectors have long presumed that as the 1930 penny and 1931 Indian penny with the dropped 1 reverse both share the Indian obverse, that the same dies were used to strike them. In 1960, James Hunt Deacon made the following comment regarding the 1931 dropped 1 penny in a South Australian Numismatic Society Journal article covering “The Story of Australia’s Coinage and Currency”: “Next we have the famous 1930 penny, which except for the overdated threepence, is the rarest coin of the series. Linked with the 1930 penny is a variety of the 1931 issue, which has the last figure of the date rather out of line with the other three. This is probably the result of the 1930 die being re-engraved with the 1931 date. This is quite easy to distinguish while examining the two varieties together.[20]

According to Mullett’s research that is not quite the case - obverse die A2B10 was indeed one of the three (Indian) obverse dies used to strike 1930 pennies on August 13th 1931, and it was also used to strike the 1931 Indian pennies with the standard (Birmingham) reverse later the same day.

However, the obverse die used on the 1931 Indian pennies with the dropped 1 reverse was labelled A2B16-107. That die was struck in “No. 3” steel[21], which is the same steel as used for obverse die number 108 - one of the other three (Indian) obverse dies used to strike the 1930 pennies in August 1931. 

Physical confirmation of this distinction can be seen when we examine examples of both coins - the 1931 dropped 1 Indian obverse pennies all have the same obverse die flaw near the “S” of “GEORGIVS”, whereas this die characteristic is not seen on all 1930 pennies.

From this, we can conclude that the relationship between the 1930 penny and the 1931 dropped 1 Indian penny is:

1. The obverse dies used to strike them were from the same hub source;

2. The obverse dies used to strike them were produced in the same type of steel, and 

3. The coins were both struck as part of the Melbourne Mint staff’s “live” trials aimed at increasing productivity during challenging economic times.

Given the very limited number of coins struck from the dies produced in No. 3 steel, it would seem that the Melbourne Mint experiments in August 1931 would have excluded it from being used from that date onwards. Mullett does not mention a formal report being prepared that summarised the result of the experimentation that was undertaken, however No. 3 steel does not seem to have been mentioned from that date onwards.

A known mintage of less than 1,000 coins for this variety ranks the 1931 Indian Dropped 1 penny among Australia’s rarest Commonwealth coins. That it was struck during the series of experiments and trials that also produced the “glamour” coin in the Commonwealth series makes it all the more compelling to own.

[1]Mullett; WJ, "Australian Coinage - An Account of Particular Coins", Self-published, Canberra, 1996, p 28.

[2]Ibid, p 8.

[3]Ibid, preface.

[4]Ibid, p 8.

[5]Ibid, p28

[6]Skinner; Ian, "Australian Coin and Banknote Values", Rennik’s Publications, Adelaide, 1989, p 41-59.

[7]"Annual report of the Deputy Master and Comptroller - Royal Mint, 1930“, Royal Mint, London, 1931

[8]Mullett, op. cit., p9

[9]Ibid, p9

[10]Ibid, p12

[11]Ibid, p10

[12]Ibid, p9

[13]Ibid, p9

[14]Ibid, p9

[15]Ibid, p1

[16]Ibid, p1

[17]Ibid, p17

[18]Ibid, p19

[19]Ibid, p19

[20]James Hunt-Deacon and Kenneth J. Irons; "The Story of Australia’s Coinage and Currency" in the Australian Numismatic Journal, 11, 1960, p 6.

[21]Mullett, op. cit., p10

Category: Commonwealth Coins