>> MINT ERROR COINS OF INDIA

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MINT ERROR COINS OF INDIA

Friends, before discussing about the mint error coins, I propose to write a few words about how the coins are made. I hope this will help my readers to understand how and why error coins are minted.
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How a coin is made:

All coins struck in India are struck by a pair of dies.  A die is a steel rod with a face that is the same size as the coins that it will be striking.  This steel rod will contain the design for one side of the coin.  Two of these steel rods (dies) are needed to strike coins.  One will have the obverse (front of the coin) design, and the other will have the reverse (back of the coin) design.

i)             How the dies are made:
First, an artist creates a large plaster model of the coin. The plaster model is then coated with rubber. The rubber mold is then used to make an epoxy galvano. Next, a Janvier reducing lathe takes a long time to reduce the image onto a steel cylinder, called as MASTER HUB. The master hub is then heat treated to make it hard. The design on the master hub is in relief (raised) and is similar to the design on the coin.

The master hub is then used to make only a few MASTER DIES via hubbing, which involves pressing the master hub into a steel blank to impress the image into the die. The design on the master die is an incused mirror image of the design on the coin.

Rather than being struck by the master die, coins are struck by Working Dies.  The master die is used as a tool from which the working dies would ultimately be produced.  For this, the master die is taken to a machine known as a hubbing press.  In the hubbing press the master die was placed above a blank steel rod.  With great pressure the face of the master die was lowered and squeezed into the steel rod leaving the impression of the image on the master die on the face of the steel rod.  The new steel rod is known as a WORKING HUB  and it now has the design images in relief (raised) just like on the struck coins.  The face of the working hub looks exactly like one side of a struck coin.

Then the working hubs are put through the same process to form the WORKING DIES. These working dies are the actual dies which will strike coins.

The difference between a HUB and a DIE is that the hub has a raised normal image and a die has an incuse mirror image.

Error in the working die may lead to

n        Doubled Die

n        Wrong design on the die

n        Terminal Die State leading to a cracked die or a broken die

ii)     How planchets, to mint the coin are made:

Metals in correct proportion are mixed and melted to prepare the alloy suitable to mint the coins. Metal bars are made from this molten alloy. These bars are fed to roller mills to prepare metal sheets of desired thickness. These metal sheets are then fed to a punching cutting machine to prepare the planchets(blanks). Long rolled sheets of metal are automatically feed into the machine. The punching-cutting machine goes up and down, cutting circular planchets out of the thin metal sheets.

Error at the time of planchet preparation:

n        Clipped error

n        OMS

n        Thick or thin planchet

iii)  Minting the coin in a coin minting press.

The working dies are set up in a machine called a coining press. In the coining presses one die would be positioned above the other.  The feeder mechanism pushes one planchets into the coining press, so that a planchet (blank) will come between the dies.  The upper die (hammer die) would come down with great force and strike the planchets, while it was resting on the lower die (anvil die).  The force of the hammer die striking the planchet on the anvil die would place the images from the dies onto the planchet and the result would be a minted coin. 

Error due to coining press malfunction:

a)     Feeder mechanism malfunction may lead to

n     Blank strike of the dies having no planchets between them, causing Ghost error

n     Off center strikes

b)    Coining press malfunction may lead to

n     Double or multiple strikes

n     Brockage (Lakhi) 

iv)   The collar:

When coins are being struck, the lower die (Anvil die) is surrounded by a collar. This collar floats on springs, which prevents damage to the coinage press, if there is a malfunction. When a planchet is fed into the coinage press, it rests inside the collar on the Anvil die (lower die). When a coin is minted, the coin blank expands, due to the high pressure exerted on it by the striking hammer die. The collar does not allow the expansion of the minted coin beyond the collar’s diameter, so all the coins minted, are of a definite uniform size.

When the obverse and reverse dies strike the planchet the planchet expands to fill the collar, impressing the collar design into the edge of the coin.

Error due to Collar malfunction or fitting of a wrong collar:

a)     Collar is out of position – Broad strike error

b)    Wrong collar fitted – Coin with a wrong collar design (Example: Hen-decagonal edge in a 1 rupee FSS and CN coin)

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When any item is mass produced in any machine, it is quite natural to find some of the items produced, to contain some error / defective samples in it. Minting of coins is no exceptions to this. As coins are minted in huge numbers, we find some error specimens coming out of the production line.

These error coins can be grouped under five major types:

a)     Striking errors

b)     Planchet errors

c)     Die errors

d)    Coins with multiple types of errors

e)    Other errors ( errors not coming under any of the 4 types described above)

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Striking Errors

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Die Adjustment Strikes / Extremely weak strikes

Die adjustment strikes are also known as die trials. This error occurs when a coin is struck from the press with very little pressure. When the press is being set up and adjusted, extremely weak strikes occur as the strike pressure reaches its optimum level. These die trials are destroyed after being struck and are rarely found in circulation.

Alternatively these weak strikes may have been made when the coining press is stopped after a day’s work is over. When the coining press is switched off, some last pieces of coins minted, may have received a very weak strike from the coining press.

From Mayank Agarwal's collection

OFF CENTER STRIKES:

Here only part of the coin blank is struck on its both sides.

How it occurs:

When coins are being struck, the lower die (reverse die) is surrounded by a collar. This collar floats on springs, which prevents damage to the coinage press, if there is a malfunction. When a planchet is fed into the coinage press, it should rest inside the collar on the reverse die (lower die).

If the planchet does not rest completely inside the collar, you will have an Off Center struck coin. Only part of the coin will show the design. Since the collar floats beside the die, it is pushed down if the planchet is resting on the collar during the striking process.

Note: To be an Off Center struck coin, both the obverse and the reverse must be equally off center and part of the design elements must be missing. If only one side of the coin is off center, it is a MAD (Mis-Aligned Die).

MAD(Mis-Alligned Die) STRIKE:

The coin shown is a MAD Strikecoin.

Mis Aligned Die Error

Here the obverse side of the coin is well centered, but the reverse side is slightly off center.

Another beautiful MAD error coin from collection of TEJAS H SHAH, my friend.

Obv -  Well centered,                                                  Rev - Off centered

Another beautiful MAD error coin from collection of ABHISHEK KHEDIA, my friend.

FROM COLLECTION OF ABHISHEK KHEDIA, KOLKATA

In this interesting MAD error coin, the obverse die is mis-aligned, but the reverse die is well centered. Due to misalignment of the cracked obverse die, the lower half of the obverse side is blank. But though the reverse die is well centered, the full design on the reverse side is not seen, the lower half portion missing any design. The cause of this abnormality is: - . While this coin was struck, though the reverse die was in correct position,  the cracked obv die was in a misaligned position. So while this coin was struck by both the dies, the lower half of the rev side did not get any design as there was no obverse die over that area to put sufficient pressure for creation of the lower half of the reverse design there, so it remained blank.

A pair of 25 paise MAD error coin from collection of RAJA BISWAS, KOLKATA, my friend

OBVERSE WELL CENTERED, REVERSE MISALIGNED

 Please mark, due to misaligned reverse die, the legend 'PAISE' on the obverse side is not well displayed.

REVERSE WELL CENTERED, OBVERSE MISALIGNED

Acknowledgement:

This pair of 25p MAD error coins are taken from the collection of my friend RAJA BISWAS of Kolkata. Many thanks to him for sending these photos for being posted in this blog. 

BROAD STRIKES:

Normally, when any coin is struck in the minting press, a collar surrounds the metal disk as the dies come together, and the coin metal is squeezed against it. Naturally, the resulting coin will have almost exactly the same diameter as the inside of the collar. So all coins of a particular denomination are of uniform size.

When some dirt or debris lodge between the collar and the lower die, it inhibits the free movement of the collar. When the collar is not there (is out of position), the coin metal is unrestrained and an over-sized coin results. These types of coins are called broad strikes.

5 Rupees Ni - Br,  Broad Strike

2 Rupees Mudra - FSS,  Broad Strike

Note:  If the entire design is visible on the off center error coin, it is considered as a broadstrike. If, however, any part of the design is missing due to the coin not being centered under the die, then it's considered to be an off center error. The broad strike coins are a bit larger in size than the normal coin.

DOUBLE STRIKE:

When a coin is first struck as a well-centered coin, but is struck again before the coin could leave the coining chamber, a Double Strike coin is created.

Double strikes are of two main types:

i) Double strikes with the second strike OFF CENTER.

In this type of error coin, both sides of the coin shows a normal strike and an off-center double impression.

The above specimens are 2 rupees National integration off center double struck coins.

1954 - 1 Pice Horse - Mumbai Mint - 

The double struck coin shown above is a 1954-1 pice- Mumbai issue, taken from the collection of my friend Rahul Mittapally of Hyderabad. Many thanks for sending this coin photo to me. This double strike coin is created out side mint, hence a fake double strike.

How it occurs:

In this type of error coins, a coin is first struck as a well-centered coin, but is struck again after the coins moves some distance, covering part of the die.

  

ii) Double strikes with both strikes OFF CENTER.
In this type of error coin, both sides of the coin shows both strikes in off-center position.

How it occurs:

Here the coin is first struck before the coin blank fully rests on the lower die. It is struck again before the coin is ejected from the minting press.

Acknowledgement:

This 1 rupee FSS coin of 1997, shown above, is collected by my friend Mr. Tejas H Shah, of Mumbai. I am thankful to him for allowing me to use the images of his coin in my blog.

QUADRUPLE STRIKE  (A KOHINOOR IN ERROR COINS):

Here you will find 4 strikes on a 2 rupees ‘R’ symbol coin. This wonderful error coin belongs to the collection of my friend Mr. Tejash H Shah of Mumbai. He was very kind for allowing me to post its photo on this blog.

FLIPPED DOUBLE STRIKES:

Flipped Double Strikes are first struck normally, then turned up-side-down (and perhaps rotated) and struck again.

5 Rupees CN - Flipped double Strike

How it occurs:

The planchet is fed into the coinage press and rest inside the collar on the anvil die (Reverse die). After being struck, the anvil die moves upward, raising the coin. Now the coin is supposed to exit the coinage press and go to a collecting area.

If the coin does not eject properly and spins, it falls back inside the collar. The second strike is totally at random. It is possible for the coin to settle back inside the collar and be struck the second time with opposite dies. Though this is very rare, it does occur at times.

DOUBLE DENOMINATION:

Here one coin is struck on a previously struck coin. This is deliberately made in some countries, in which when a ruler is changed, new coins showing his effigy and his name are minted on previously circulating coins, instead of minting those on fresh new blanks. It is also done by mistake in some countries like USA where a half dollar struck on struck dime, a cent struck on struck dime etc are reported.

But this type of error is very unusual in case of Indian coins. In the coin photo given below, you will find that a 1 rupee ear of corn design coin of 2004 was first minted on the blank. Again a 1 rupee cross design coin of 2005 was struck on that previously struck 1 rupee ear of corn design coin of 2004.

obv of 2005 on rev of 2004, 1 rupee          rev of 2005 on obv of 2004, 1 rupee

Note: You can find faint impressions of "Rupaye" in Hindi and year of issue 2004 of the previously struck 1 rupee "ear of corn" design rupee coin, on the obverse side of the 1 rupee cross coin. Again you can find a part of the Lion capitol on the cross on the reverse side. 

Acknowledgement: Many thanks to Mr. Tejas H Shah of Mumbai for allowing me to post the photo of this coin from his collection.

BROCKAGES: (Lakhi Coins)

Brockages are specimens of coins, those are found with normal design on one side and a part of the same design or the same design in full, incused or stamped on the other side also. These are also called as “Lakhi” coins. 

Two types of Brockages are generally found:

i) A Full Brockage: (Mirror Brockage)

A Full Brockage will have the same picture and wording on both sides of the coin, but on one of those sides, everything is backwards. Also, everything is 'set in' to the coin surface, instead of raised. It results when one of the Coining Dies is completely covered by a previously struck coin.

             Full Brockages are of two types.


     a) Obverse Full Brockage:
         Here on both sides of the coin the obverse image is found.

1 Rupee Cupro-Nickel -  Full Obverse Brockage

       b) Reverse Full Brockage:
         Here on both sides of the coin the reverse image is found.

1 Rupee Cupro-Nickel -  Full Reverse Brockage

Note: This, Reverse Brockage error shown above, is very rare to find
.

Acknowledgement:

This 1 Rupee Cupro-Nickel Reverse Brockage coin shown above, is actually collected by one of my friends, Mr.  Abhay Agrawal, of Gwalior.  He was kind enough, to allow me to use his coin photo in this blog. Many many thanks to him.

How full brockage occurs? 

This happens when the coin last struck in the chain gets lodged in the die and then another blank comes into position and is struck. The new blank gets the normal impression on one side. The coin, still stuck in the die, acts as a die and the other side of the blank receives an incused impression from the face of the previous lodged coin.

ii) A Partial Brockage:

In a coin with Partial Brockage, we find normal design on one side and a part of the same design is found incused or stamped on the other side.

How partial brockage occurs? 

This type of brockage is formed when a coin, after being minted, is not ejected from the press and remains covering only a small part of one die, while another planchet is struck. The result is that, the portion of the first coin covering part of one die, acts as a die for the second coin blank and makes an incuse impression of the exposed face.

Types of Partial Brockage:

Two types of partial brockage are generally found.

a) Partial brockage caused when the first coin is a full minted Normal coin:

Subhas Bose- Partial Brockage 

Here  some incused text in reverse is found on the obverse face of the coin.

1 Rupee FSS- Partial Brockage

In the above coin, a part of the lion capitol, a part of "Satyameva Jayate" is found incused on the reverse side.

b) Partial brockage caused when the first coin is an off center error coin:

  

The error coin shown above is from the collection of my friend Tejas H Shah of Mumbai. It has been created by an off center coin sticking to the die. This type of error is very rare.

DIE CAP:

At times, a coin will stick to a die and be struck several times with a die. The more times the coin is struck, the more the metal from the coin moves up and around the die. Some of them can resemble a bottle cap, thus the term DIE CAP.

Die Cap Error

Die Cap Error from Abhaya's collection

Acknowledgement:

This 50 paise Die Cap Error coin is actually collected by one of my friends, Mr.  Abhay Agrawal, of Gwalior.  He was kind enough, to allow me to use his coin photo in this blog. Many many thanks to him.

INDENTS:

An indent error occurs when two blanks are fed inadvertently into the same collar, with one blank partly overlaying on top of the other. When the hammer die strikes this combination, the upper blank will be forced into the lower blank, creating a depression on the lower blank, which is shaped similar to the upper blank. The upper blank gets a shifted image on its upper side, and its lower side having no image at all, thus creating an UNIFACE strike.

Indent Error

UNIFACE STRIKES:

A coin having no design on one of its faces is called an Uniface coin. We find many types of UNIFACE coins.

Full design on one side and other side blank:

It occurs when there have been two blank planchets in the press at the same time, the upper blank fully covering the lower coin blank. The upper blank will obstruct the upper die from having the upper design on the lower blank, and the lower blank will obstruct the lower die from having the lower design on the upper blank. So both the blanks become uniface coins.

50 paise - Uniface coin

Shifted strike on one side and other side blank:

It occurs, when there have been two blank planchets in the press at the same time, the upper blank partially covering the lower blank. In this situation, the upper blank will partially obstruct the upper die from having the complete upper design on the lower blank, and the lower blank gets an indent error. As the lower blank completely obstructs the lower die, the upper blank gets no design on its lower side and only gets a shifted strike on its upper side.

Uniface strike due to a die cap:

When a die cap remains adhered to a die for a long time, the design on the exposed face of the die cap, becomes indistinct and coins minted at that time are found to be uniface.

Note: A very indistinct image of a Rhino is found on the reverse side.

MATED PAIR:

A planchet fall inside the collar and a previously struck coin fall on the collar, partially covering the coin blank. If the two are struck with the dies, you can have a mated pair. Each coin of a mated pair is each struck at least twice. Some may be struck several times. The odds of finding them are very rare.

Upper coin of a mated Pair 

Note: Its partner is not yet found by me.

Struck through error:

This type of error occurs when a foreign object lies on top of the planchet and leaves an impression of itself when struck into the coin. A wide variety of objects, such as a string, a piece of cloth, a metal wire, hair, plastic articles or staples. etc, have been reported causing this error.

Struck through error on the reverse side:

Struck through error on the obverse side:

In the error coin shown above a metal wire lying on the planchet has left a curved incused line on the surface of the obverse side of the minted coin.

Acknowledgement: Many thanks to Shakil Ahmed of Kolkata for sending this coin photo from his collection to be posted in this blog.

36**BLANK PLANCHET:

         These are of two types: one which has been freshly cut in the blanking press (Type One), and one which has slightly raised rims after going through a softening process (Type Two). They simply slipped by the striking presses.

Blank Planchet for 5 Rupees Nickel - Brass coin

Blank Planchet with rim in 5 Rupees CN coin ( From album of Tejas H Shah)

Blank Planchet for 50 Paise FSS coin

Acknowledgement:

This 50 paise blank coin was actually collected by one of my friends, Mr. C.G.Bhargav of Chennai. He was kind enough, to gift me this specimen for my collection. Many many thanks to him.

EDGE ERRORS: 

Security Edge Missing:

Normally high value coins are produced with a 'Security edge'. This is done to check counterfeiting of coins. Coins having 'security edge' are first struck with the usual upright milling, at the time the obverse and reverse designs are impressed upon them. These are next passed through a second press, where the security mark is put on the edge, under pressure.

But, while being fed into the second machine, if a few coins accidentally skip the press, these may go to circulation with normal upright milling. Thus we find another type of error in coin specimens with upright milling which should have a 'security edge'.

A 5 rupees Cupro- Nickel coin with a milled edge.

Plain edge in place of Milled edge:

To lower the production cost, in later parts of 1990, Government of India instructed mints to put milled edge on 1 rupee coins from 1991. But some 1 rupee Fss coins minted during 1992 to 1996 are with plain edge in place of milled edge.

DIE CLASH / GHOSTING ERROR:

When the upper die moves downwards to strike a coin when no coin blank is there in between, both the dies strike each other. At this high pressure of the strike, some designs of the obverse die is left on the reverse die in relief and some designs of the reverse die is left on the obverse die in relief. When any fresh blank is minted by those dies, an incused image of some text or design of the obverse die is found on the reverse side of the coin and vice versa also occurs. This type of error is called Die clash error / Ghosting error.

Indira Ghost error

National Integration - Ghost error 

Cellular Jail - Ghost error 

Note: This error is very common in case of 2 rupees National integration Cupro-Nickel coins.

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Planchet Errors

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COIN STRUCK ON A WRONG SIZE BLANK:

When a coin is struck on a wrong planchet, this means that a coin was struck on the blank (planchet) that was made for another denomination. Some examples would be a 50 paise planchet struck with rupee dies, a rupee planchet struck with 2 rupees dies. Coins struck on the wrong planchets are rare.


i) 1 Rupee minted on 50 paise blank:

1 Rupee  Normal coin               1 Rupee on 50 paise blank

i) 2 Rupees minted on 1 rupee blank:

2 Rupees  Normal coin             2 Rupees on 1 rupee blank

How this error occurs?

The bins, that are used to transport the planchets from the blanking machine to the coinage press, has seams inside the bin. Sometimes a planchet will stick in the seam and not be release when the bin is emptied. Then the bin is filled with another denomination planchets but this time when the bin is emptied, all the planchet are released from the bin.

Thus a 50 paise planchet can be emptied into the rupee coinage press with thousands of rupee planchets.

CLIPPED COIN:

In some minted coins we find a portion of the coin is clipped. These types of error are called a clipped coin error. 4 types of clipped error coins are generally found.

i)                    Coins with a straight clip.

ii)                  Coins with a curved clip.

iii)                Coins with a multiple clips.

iv)                Coins with a ragged clip.

How is a clipped coin made?

A clipped coin is made long before it becomes a coin. It starts its life as a clipped planchet. This is the blank before the dies in the coinage press strike it.

A punching-cutting machine is used to make the planchets. Long rolled sheets of metal are automatically feed into the machine. The punching-cutting machine goes up and down, cutting circular planchets out of the thin metal strips.

Straight clip:

If the metal sheet is not lined up properly with the punch-cutting machine, straight clips can be formed. This is because the metal is feed into the machine to far to the right or left. The punching-cutting machine will cut circles out of the sides of the sheets, which do not fill the area cut by the punch. This leaves one side of the planchet straight. This creates a straight clip.

Curved clip:

If the metal is not feed into the punch-cutting machine at a steady speed, the movement of the metal does not keep up with the punching operation. When this happens, the machine is cutting circular planchets out of an area in the metal, that has already been cut to get a single planchet. This creates a curved clip.

From Mayank Agarwal's Collection

Multiple clips:

When the punch-cutting machine is cutting circular planchets, out of an area in the metal, that has already been cut to get more than 1 planchets, a multiple clip is created.

Multiple Clips ( 3 curved clips)

The coin shown above has 3 curved clips.

Another coin with multiple clip:

This clipped coin shown above is with 3 curved clips. Thanks to my friend Shakil Ahemad of Kolkata for providing photo of this coin from his collection.

A coin with 4 clips: ( Very rare to find)

Acknowledgement: Many thanks to Darshan Lal Baweja, of Yamunanagar , Haryana for sending this coin photo from his collection to be posted in this blog.

Ragged clip:

If the roll of metal over feeds the punch-cutting machine, the punching machine cuts the ends of the roll. This creates a ragged clip.

From Mayank's collection

COIN STRUCK ON A DIFFERENT METAL BLANK (OMS COINS):

i) Half Rupee coin struck on Brass blank in place of Nickel blank:

George VI - Half Rupee Struck on Brass

Here, the shown specimen is a George VI half rupee brass coin, which is supposed to be minted in Nickel. Perhaps this occurred by mistake as the minting of the half rupee was done with planchet prepared from brass sheets, which was used for minting of brass ½ Anna or 1 Anna or 2 Anna coins. 
This coin may be forgery, made for circulation during that period.

ii) Two Rupees NI coin struck on Nickel blank in place of Cupro-Nickel blank:

Magnetic 2 Rupees National Integration coin

The coin shown above is issued by Kolkata mint in the year 1998. It is a regular issue on the theme "National Integration". Normally all the hen-decagonal shaped National Integration coins were issued in India during 1992 to 2004 in Cupro-Nickel alloy and are non magnetic. But this coin was wrongly minted using pure Nickel and is magnetic. 

iii) Two Rupees NI coin struck on 1 rupee FSS blanks in place of Cupro-Nickel blanks:

2 RUPEES NI 1992, KOLKATA MINT, MINTED ON 1 RUPEE FSS BLANK

2 RUPEES NI 1994, HYDERABAD MINT, MINTED ON 1 RUPEE FSS BLANK

The coins shown above are issued by Kolkata and hyderabad mints. These are a regular issue on the theme "National Integration". Normally all the hen-decagonal shaped National Integration coins were issued in India during 1992 to 2004 in Cupro-Nickel alloy and are non magnetic. But these coins were wrongly minted on ESS blanks intended to mint 1 re regular coins. So these OMS coins are magnetic.

Acknowledgement: Thanks to my friend MD TANWER ALAM of Howrah, for providing the photo of this coin from his collection, to be posted in this blog.

2 RUPEES NI 2002, HYDERABAD MINT, MINTED ON 1 RUPEE FSS BLANK

Acknowledgement: Thanks to my friend KUNAL JAIN of Hyderabad, for providing the photo of this coin from his collection, to be posted in this blog.

iv) Five Rupees Saheed Bhagat Singh coin struck on Nickel-Brass blank in place of FSS blank:

Bhagat Singh OMS

The coin shown above is issued by Hyderabad mint in the year 2012. It is a commemorative issue on "SAHEED BHAGAT SINGH". Normally Bhagat Singh  coins were issued in India  in FSS alloy and are magnetic. But this coin was wrongly minted using  Nickel-Brass blanks and is non-magnetic. 

Acknowledgement: Thanks to KUNAL JAIN for providing the photo of this coin, which is posted in this blog.

v) Five Rupees 'R'  symbol regular coin struck on 5 rs FSS- blanks (on which Saheed Bhagat Singh coin was minted), in place of Nickel-Brass blank:

5 RS 'R' - 2011 REGULAR, HYDERABAD MINT, MINTED ON 5 RS BHAGAT SINGH FSS BLANK

The coin shown above is issued by Hyderabad mint in the year 2011. It is a regular issue showing the "Rupee" symbol.  Normally these  "Rupee".symbol.5 rupees coins were issued in India  in Nickel-Brass alloy and are non-magnetic. But this OMS coin was wrongly minted using  FSS blanks, prepared to mint 'Saheed Bhagat Singh' commemorative coin and it is magnetic. and its weight equals to the weight of 'Saheed Bhagat Singh' commemorative coin. This is one of the  very rare OMS coins of India.

Acknowledgement: Thanks to my friend ABHISHEK KHEDIA of KOLKATA,, for providing the photo of this coin from his collection, to be posted in this blog.

vi) Five Rupees Waves coin struck on Cupro-Nickel- blank in place of FSS blank:

5 rs waves, 2007 Kolkata, OMS coin, minted on Cupro-Nickel blank

The coin shown above is issued by Kolkata mint in the year 2007. It is a regular issue on the theme "IT & Connectivity", popularly called as Waves coins. Normally Waves  coins were issued in India  in FSS alloy and are magnetic. But this coin was wrongly minted using  Cupro-Nickel blanks and is non-magnetic. This is one of the  very rare OMS coins of India.

Acknowledgement: Thanks to my friend MD TANWER ALAM of Howrah, for providing the photo of this coin from his collection, to be posted in this blog.

vii) Five Rupees 'R'  symbol regular coin struck on 1re FSS- blanks in place of Nickel-Brass blank:

5 RS 'R' - 2011 REGULAR, KOLKATA MINT, MINTED ON 1 RUPEE FSS BLANK

5 RS 'R' - 2012 REGULAR, KOLKATA MINT, MINTED ON 1 RUPEE FSS BLANK

5 RS 'R' - 2013 REGULAR, KOLKATA MINT, MINTED ON 1 RUPEE FSS BLANK

The coins shown above are issued by Kolkata mint in the years 20011, 2012 and 2013. These are regular issue on the theme "R symbol coins", . Normally these coins were issued in India  in Nickel-Brass alloy and are non-magnetic. But these coin were wrongly minted using  1 rupee-FSS blanks and are strongly magnetic. Their weight is also same with the weifgt of 1 re 'R' symbol coins..

Acknowledgement: Thanks to my friend MD TANWER ALAM of Howrah, for providing the photo of this coin from his collection, to be posted in this blog.

iii) Two Rupees TUKARAM coin struck on 1 rupee FSS blanks in place of Cupro-Nickel blanks (Noida Issue):

TUKARAM OMS

The 2 rupees issue commemorating TUKARAM is issued in Copper-Nickel alloy. But this coin was wrongly minted on a 1 rupee FSS flan, Hence an OMS.

Acknowledgement – Many thanks to Mohit kaura of Batala, for sending the photo of this OMS coin from his collection to be posted in this blog.

CRACKED COIN BLANK:

Some specimens of minted coins show some cracks . This happens when a CRACKED  coin blank is fed to the coining press.

Cracked Coin Blank

Cracked from side (From Mayank Agarwal's collection)

LAMINATION ERROR:
A lamination is a planchet defect originating when a portion of the coin metal separates from itself due to impurities or internal stresses. Lamination flaws occur primarily when foreign materials or gas oxide becomes trapped within the planchet.

Obverse chipped 

Reverse chipped 

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Die Errors

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 Die Doubling Error:.

In this type of error coin, one side of the coin shows a normal strike and the other side shows an double impression. Here in the error coin shown below, the reverse side is normal but the obverse side shows doubled impressions.

Obverse side is double struck on - center

The specimen shown below is another doubled die strike 

Taken from Tejas H Shah's Album

My recent collection of 2012 - 5 rs regular - Hyd issue, with Die Doubling Error:

How it occurs:

Die doubling:

Because of the hardness of the die steel and the amount of pressure that needed to be applied for the image transfer, it took more than one squeeze (hubbing) of the master die into the face of the working hub to leave a satisfactory impression of the design on the working hub.  After it received the first impression, the working hub was removed from the hubbing press and treated with heat (annealed) to relax the molecular structure of the alloy and allow another impression to be made by again squeezing the master die into the working hub.  This process of making an impression (hubbing) and heat treating (annealing) was repeated until it was deemed that the image on the working hub was satisfactory.

Working hubs produced from the master die were then in turn used in the hubbing press to make the Working Dies.  It is the working dies that are then used to strike the coins.  Like the working hub, it took more than one squeeze of the working hub into the working die to leave a satisfactory impression of the design on the working die.  This meant that the working die had to be removed from the hubbing press after each hubbing and heat treated before receiving the next impression.

If, when the die is subjected to another hubbing, it is not lined up exactly with the hub, the result is a secondary image, or doubling. This is called die doubling.

Acknowledgement:

The 2 rs Nritya Mudra coin shown on the top is collected by my friend Mr. Mayank Agarwal, of Varanasi. The 25 paise Rhino coin shown under it, is collected by my friend Mr. Tejas H Shah, of Mumbai. I am thankful to both of them for allowing me to use the images of their coins in my blog.

Note:

Previously I had a wrong conception that, the coin is first struck as a well-centered coin, but a loose obverse die twists slightly and strikes again. So I named this type of error as "Doubled strike-On center". But I found this type of error only on some 25 paise Rhino coins and .2 rs Mudra coins of some specific years issued from Hyderabad mint. Had it been a general error it would have been seen issues of many years, on different coins by other mints, but it was never found. So I changed this entry to be doubled die error. 

I'm extremely sorry for this fault of mine.

DIE CRACK ERROR:

At times, during the minting process, a die develops cracks. Coins minted with that cracked die are known as die crack error coins. The crack may be a single crack or multiple cracks. 


a) Die with a single crack: 
    i) Both portions of the cracked die are in the same level:
           When a coin blank is minted using such a die , a raised hair line is seen on the coin face.

Coin minted with a die having a single crack 

 ii) The small cracked portions of  the die is in a higher level than the rest:
         In this case a smaller portion of the coins remains in lower level than the rest.

iii) The small cracked portions of  the die is in a lower level than the rest:
        In this case a smaller portion of the coin remains in raised level than the rest.

b) Die with multiple cracks:

    When coins are minted using a die with multiple cracks, they show a portion of the coin design in an area, lower / higher to the coin surface.

From album of Tejas H Shah

Acknowledgement:

The coin shown above is collected by my friend Mr. Tejas H Shah, of Mumbai, one of the greatest collector of error coins in India. I am thankful to him for allowing me to use the image of his coin in my blog.

DIE BREAKS (CUDS):

At times, a part of a die breaks and falls off. When a coin blank is minted with this broken die, the missing portion of the die allows the metal of the planchet to fill this broken area, making a raised blank area. This type of error is called a CUD error.

Cud Error in 1 rupee coins

Cud Error in 5 rupees and 50 paise coins

Cud Error in 10 p, 25 p and 2  rupees coins

Die Chip Error:
At times a small chip of metal that breaks away from the surface of a die, creating a void that coinage metal flows into during striking. Usually seen as a small raised lump on a coin.
(Photo of coins having this error will be posted soon)

DIE AXIS ROTATION:

While minting a coin, both the dies are kept in such a position, that the top most design of the obverse and reverse coin exactly face each other. This type of error occurs, when one of the dies is rotated with respect to the other die. In this type of error, the Obverse / Reverse Die is rotated, anywhere from 5-180 degrees clockwise or counterclockwise.

This rotational error is also described by some people as different hours of the clock. For example a clockwise rotation of 90 degree, is called as 3 O’clock rotation error. Similarly a 180 degree rotation, is called as 6 O’clock rotation error and a 90 degree counter clockwise rotation, is called as 9 O’clock rotation error.

6 O'clock Rotation

A WONDERFUL COLLECTION OF DIE AXIS ROTATION BI-METAL COINS COLLECTED BY MY FRIEND, MAYANK AGRAWAL OF VARANASI:

MULES:

The coins minted with the obverse die of one coin and reverse die of another coin, are known as Mule Coins. Mules are sometimes accidentally produced at the time of re-striking coins of earlier periods. Unless the obverse and reverse dies are properly paired at the time of restriking, the coins struck may have the wrong obverse or wrong reverse.

Indira - 50 paise - Mule

How this occurs?

The above picture shows a Mule Indira Gandhi, 50p coin. On the normal Indira Gandhi, 50p coins, a dotted circle is present on both the obverse and reverse sides. In 1986 another 50p coin was issued on the theme Fisheries and there was no dotted circle on either sides of that coin. By mistake, on some day in the year 1986, the reverse die of Indira Gandhi, 50 p coin, was paired with the obverse die of Fisheries, 50p coin, for minting of Indira Gandhi, 50 p coin, and this resulted this mule coin.

Note: To see the other Mule coins issued in India, please visit the page, “Mule coins of India”.

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Coins with multiple Types of Errors

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UNIFACE + BROCKAGE ON THE SAME COIN: 

How this error might have created:

This error coin is collected by Dr. Pv Bharat. The sequence of events of its creation may be like this. First a blank enters the coining press and it is normally minted. Then it adheres to the Obv die and not ejected from the press. Next due to  some technical errors, 2 blanks are fed to the coining chamber and the minting process continued. In this situation, the blank facing the reverse die will get the reverse impression on one side and uniface on the other side. The middle blank will be uniface on one side and get the brockage impression from the previously minted coin adhering to the Obv die.

MIILLED EDGE + CLIPPED PLANCHET ON THE SAME COIN:

                   Obverse                                            Reverse                           Edge

DETAILS OF ERROR PRESENT:

The coin shown above is minted from a clipped planchet. More over though all the 5 rupees Cupro-Nickel Regular coins issued india have a security edge, this 5 rupees CN coin issued by Kolkata mint has a milled edge, an error.

STRAIGHT CLIP + OFF CENTER ON THE SAME COIN: 

From the collection of Darshan Lal Baweja

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Other Errors

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PRE ISSUE:

Netaji Subhash Chandra bose was born in the year 1897. So, 1997 is the centenary year of his birth. But due to mistakes, the Kolkata mint issued a commemorative coin in his honour in the year 1996. This coin was withdrawn due to protest from all circles and re issued in 1997.

2 Rs - Netaji Subhas Chandra Bose -1996

Note: This is one of the RARE coins of Republic India.


WRONG NAME OF THE COUNTRY ON THE COIN:

10 paise coins in FSS were issues from the year 1988. But inadvertently, some coins issued by Kolkata mint in 1988 and 1989, shows the name of the country as “Marat” in Hindi, in place of “Bharat”

Note: This is one of the SCARCE coins of Republic India.

ADDITION OF “JEE” IN HINDI, IN 5 RUPEES BAL GANGADHAR TILAK COMMEMORATIVE CUPRO-NICKEL COIN:

A 5 rupees commemorative coin was issued in 2007 in commemoration of 150 years of birth anniversary of Lokmanya Bal Gangadhar Tilak. Inadvertently, in Hindi his name was written as “Tilakji” in place of “Tilak”. Due to protests from various sectors, this coin was withdrawn, a fresh die was prepared with “Tilak”, new coins were minted and issued.

Tilak Ji coin

Note: This is one of the RARE coins of Republic India.


CRACKED SURFACE ERROR:

The coin shown below shows multiple cracks on its both faces, resembling a drought affected land. The cause of this error is not known to me.

Multiple Crack Lines on both Obverse and Reverse sides

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Acknowledgement:

I have taken the help of the following web-site for preparation of this page.

i) http://www.bakercoins.net/learn/error.ed/index.html

ii) http://littlemistakes.com/WorldErrors/misstrikes/misstrikes.html

I have used some photographs from the collection of the following collector friends

i) Mr. Mayank Agarwal of Varanasi 
ii) Mr. Tejas H Shah of Mumbai 
iii) Mr. Abhay Agrawal of Gwalior
iv) Mr. Shakil Ahemad of Kolkata
v) Mr. Kunal Jain, Hyderabad
vi) Dr. PV Bharat, Lucknow
vii) Mr. Vaidya Nadhan R, Chennai

                                  I am very much thankful to all of them..

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