Every country has its own coins, irrespective of the metal or substance with which it is made from. Nowadays, coins are made from silver, gold, copper, zinc, or a combination of these metals.
1.1, Origin and history
Coins have a long history that spanned from the ancient times to the present age. A great part of this history is concerned about the economic usefulness of coins.
Although, the first set of coins in history was used for a religious purpose. Devout worshippers at the Ephesus’ great Temple of Artemis would put the coins under the temples while worshipping their gods.
The Lydian Lion coins were made from electrum, which happened to be an alloy of silver and gold that occur naturally. Alyettes of Lydia, 610-560 BC minted the Lydian Lion coins, and it was not long before people started using coins for trades and commerce.
However, Persian daric was the first gold coin discovered on earth. Some centuries after that, the Byzantine Empire minted several thin gold coins that had the image of the Christian coin.
Tong Bao, the first cast copper money was discovered in 11th Century BCE in China, and it was reportedly used during the Warring States Period and by people who lived in Shang and Han Dynasty.
Even from the ancient times, the coins were minted using different, old-styled coin press making machines. So, the coins produced then came in different styles, sizes, and designs.
Today, gold coins remain the most important examples of coins. There are basically four types of gold coins:
- Bullion coins: These are coins recognized as valuable possessions based on their gold content. For examples, the Canadian Maple Leaf, Chinese Gold Pandas, American Eagles, and the South African Kruggerrand are bullion coins.
- Numismatic coins: These types of gold coins have unlimited value, and they are mainly targeted by coin collectors. They could be sold for a lot of money based on their historical relevance, quality, grading, rarity, and circulation.
- Proof coins:These coins are minted carefully and attention is paid to their sharpness and design. Even when in circulation, these coins do not suffer any damage when mishandled or tampered with. The coins are “proof” to maintain their designs; in other words, it means that the die is treated and polished in a special way, and the coin is struck twice for an extra layer to be added to its detail.
- Counterfeit gold coins:There are imitation gold coins produced by some criminals whose intention is to fool gold coin investors and collectors. The fake gold coins, made mostly from tungsten, are sold to collectors or investors for the same price of the genuine gold coins. This illegal trade has been in existence for ages, and it is still in practice today. So, it is important to test the quality of gold coins before buying them.
In addition to this, gold coins also come in different shapes as explained below:
Round gold coin: The shape is a perfect round, and there are no rough edges on the coin.
Square gold coin: A square gold coin is neatly designed so that its edges are smooth and produces a nice feeling when touched.
Star Trek gold coin: There are some gold coins designed after themed events or popular movies. Here is a Star Trek-influenced coin.
1.3, Business value and investment market
Collectively, gold coins have some business value and investment significance. Highlighted below are some information for you bout the economic and commercial importance of gold coins:
- The meaning of the collection of coins: For a long time, some people who are called gold collectors have taken it upon themselves to collect gold coins and other gold trinkets that have high value and commercial usefulness. They buy gold coins, for example, and sell them at a higher price using different methods. It could be through an option, direct sale, or by any other means. Each gold coin collector specializes on a special coin, depending on what the customers or investors that buy the coins from them want. The gold collectors today are still doing the same thing. However, the occurrence of counterfeit gold coins has made the practice very risky. This is because gold collectors in this age must make sure the quality of the gold coins they are collecting or buying is genuine.
- Ancient gold coin auction: In the ancient times, people engage in gold coin auction. In this case, many gold collectors will participate in the auction, and the highest bidder (the collector willing to pay the highest price) will get the auctioned gold coins. People still do gold coin auction these days; in fact, there is online gold coin auction, but the final buyer will not pay for the gold coin until its quality has been confirmed. For anyone interested in investing gold, participating in gold coin auction is the best way to start.
- Investment value: Unlike other precious metals, gold has an intrinsic value that can last for a long time. Over the years, the value of gold has increased by three or four folds. If you are active trader or collector of gold coins, you will see that gold has enjoyed a huge gain in its investment value in the past five years. So, if you are interested in a short- or long-term investment, you can bet on gold. It is the only precious metal that has been able to maintain its investment or commercial value for a long time.
Bullion logo stamping production process
This chapter will introduce you to the various bullion stamping logo production processes that are common in recent years. You will also discover the different types of coin minting machines used in producing casting bullion. There are some relevant information about custom molds and the use of hydraulic presses in making them.
How do you do a bullion logo stamping? You surely need a logo stamping machine. Superbmelt logo stamping machines are specifically designed to smoothly handle the matching of gold ingot production line. With it, you can emboss different sizes of gold ingots. As a hydraulic system, the machines work when you apply hydraulic or fluid pressure to the cylinder that was attached to the object being pressed.
Bullion logo stamping machine, picture obtained from Superbmelt
These are the simple procedures required to stamp a logo or logos on your gold bar or object:
- Start the machine
- Put the gold bar inside the opened cubicle
- This means that the cast bullion is being placed under the pressure of small tonnage (20-40 tons)
- Finish with a custom mold by pressing the pattern on the gold bar. The usually pressed pattern is concave.
2.2, step 1: Casting bullion
If you are going to cast your bullion before stamping logos on it, you will need a vacuum gold bar casting machine to do that.
A vacuum gold bar casting machine, picture obtained from Superbmelt
The features and benefits of a vacuum gold bar casting machine
- The PLC control system of this gold ingot making machine takes charge of all your casting process operations. You’ll only need a few hands for your casting operations. The controller automatically takes care of almost all the operations that you might be needing workers for.
- With the SuperbMelt gold bar making machine, you’ll never have to worry about the quality of your bars as the machine is already approved for LMBA deals.
- With the vacuum gold bullion making machine, you are guaranteed of a high reduction in your power consumption.
- An overall increase in your process efficiency is guaranteed.
- This machine powerful induction generator that can in no time heat up your precious metal to any desired melting temperature.
- Safety was considered as a key factor during the design of the SuperbMelt gold bar casting equipment.
- There are numerous alarm systems positioned at strategic places within this machine. They can detect any slight of deviation from your process working condition.
- This machine can also easily detect when there is a system overvoltage or shortage of water supply.
- SuperbMelt vacuum gold bar casting machine (SPB-JD) when compared with the traditional methods of gold casting. They can be operated smokeless without having to pollute the environment. The machine is equipped with the latest green technology in the gold bar industry. This technology ensures that all pollutants are trapped from making contact with the atmosphere. Thereby preventing the environment from getting polluted.
How to operate a vacuum bullion casting machine
Operating a vacuum gold bar casting machine is simple and straightforward. All you need to do is to follow these steps:
STEP 1: Weigh the material and pour it into the mold. Nowadays, the mold can be of different shapes, such as rectangular, round, square, oval, et cetera.
STEP 2: Turn on the main power switch.
STEP 3: Set the parameters such as the timing of heating, vacuum, cooling, and alarm.
STEP 4: Press “Tank Head Switch” to open its cover.
STEP 5: Press “cooler switch” to lift cooling board.
STEP 6: Press “auto” to start casting. Vacuum protects bar from oxidation and porosity.
STEP 7: Finish the casting.
At the end of these processes, you will obtain bullion with mirror surfaces. They are already protected from oxidation, shrinkage, and porosity.
Modern vacuum gold bar casting machine versus traditional casting methods
The comparison table presents the striking differences between vacuum gold bar casting machine and traditional casting methods:
|Characteristic||Modern vacuum gold bar casting machine||Traditional methods|
|Process||The material is securely melted inside the mold under a vacuum condition||The material is melted openly into the mold|
|Oxidation||No oxidation||There is some oxidation|
|Effect on the environment||Safe||May be dangerous to the environment because of open heat|
|Technique||Vacuum-based casting||Lost-wax casting|
|Purity||Higher purity||Lower purity|
|Labor||Not labor-intensive because the PLC control system automatically controls the casting procedure. You will only need a few workers||Labor-intensive—it requires a lot of workers to complete the operations|
|Operations||It can be operated with no flame and causes no ripples||It requires flame to work; your final product may have ripples|
|Advantages||It is cost-efficient and effective||It costs a lot and may contain impurities|
The finished product (cast gold bars/bullion)
When you use the coin casting kit, including the modern vacuum bullion casting machine, the final/finished product comes out clean, shiny (with mirror surfaces), and it is ready to be stamped with the appropriate logos. In addition to this, the cast gold bars are flat and with good density. Since the bullion do not have contact with the air, they are usually smooth and are unaffected by porosity. You also cannot find any bubbles in them.
2.3, step 2: Custom molds and the use of hydraulic coin presses
Even though the gold texture is soft, you may still need dozens of tons of presses to press out the required patterns and logos. When customizing molds, you should pay attention to the following criteria:
- Material: What kind of material are you using? If it is gold, are you sure it is genuine or counterfeit gold material? This is because the quality of each mold depends on the material used in casting it.
- Shape:What is your desired customized shape? Gold molds can be shaped as a rectangle, circle (round), square, an oval, or even a triangle.
- Designs/patterns:You also need to customize the patterns or designs of the logos that will be embossed on the gold bars.
- Quality:Hydraulic coin presses are designed to help you produce high-quality custom molds. However, you must understand how these machines work.
Coin minting production process
The coins you see in the market are made through some processes that will be discussed in this chapter. These processes are called coin-minting production. And you need a coin minting press to do it.
Unlike simple coin stamping, coin minting uses a high-tonnage press to coin the
corresponding patterns, including the mirror effect of the gold coin.
Gold minting is generally highlighted, and the bright face is divided into concave parts, which is why it is different from simple logo stamping.
Double-sided printing is currently the most popular style in the world. Which entails that a single coin will have its two sides embossed.
There are four unique processes required to produce a minted coin. These procedures are described below for your reading pleasure.
3.1, Casting gold sheet
The very first step in minting a gold coin is to cast the gold sheet that will be used to make it.
3.1.1 Make gold into sheet
Coinage materials such as gold or silver materials are fed into tan electric furnace, and ingots are made through a process of continuous casting. The ingots are then rolled into sheets by using a rolling machine.
The primary reason for making a gold sheet is to make easy for future processing. It may be difficult to produce coins from gold ingots. However, with gold sheets, you can cut out the coins without too much problem.
3.1.2 What are the benefits of a good sheet for the finished product?
A good sheet has some great benefits for the finished product. Some of these admirable qualities include:
- High density: The coins will have high density; this means that they will not be too light and won’t be easily swept by wind.
- No impurities: Since the sheet was made from an ingot that has been cast using an electric furnace. The impurities have been removed from the gold sheet in the process.
- No pores: The sheet will not have any pores or holes in it. It has already been finely produced and uniformly rolled with the rolling machine.
- No oxidation: The gold sheet is protected from oxidation because of the vacuum in the electric furnace. So, it still retains original sheen or shinning appearance.
All the qualities of the gold sheet described above help the gold coins to retain or maintain their shape for a long time.
3.1.3 Where is the difficulty of making a sheet, why our machine can do it
Here is the secret behind producing a high-quality gold sheet that has high density, no impurities, no pores, no oxidation, etcetera: Using a gold coin machine such as Superbmelt continuous casting machine or gold bar casting machine, both shown below. These machines some great features that separate them from others in the market.
Some problems to avoid while casting gold sheet
Everyone wants to have a perfect gold sheet casting. In this case, you must do everything within your power to avoid the following problems while casting your gold sheet:
- Don’t ever use a counterfeit gold material to make the sheets. It will destroy the main quality of your gold coins. This warning is also applicable to other coins such as silver coins.
- Allow the gold materials to melt well—never interfere with the melting process, because if the gold materials do not melt well, it may affect both their physical and metallurgical properties.
- Don’t use a machine that already contains some impurities. This may affect the overall quality of the gold coins. Always make sure the coin-making machines are in their best states.
3.2, Roll the sheet into the required thickness
The second stage in the gold coin minting process is rolling the gold sheet into the required thickness. The ingots are heated in the pit. While hot, they are rolled out into a desirable thickness and produced in a coil shape. After that, rough and finishing rolling will be done so that the rolling plates can have the thickness of the coins to be minted or produced.
3.2.1 What are the precious metal rolling mills on the market
There are two different types of metal rolling mills on the market. They are automatic and manual metal rolling machines.
The main difference between the two types of metal rolling machines is that the manual one is operated by hand while the automatic one can be continuously and automatically operated once it has been configured to do so.
For the automatic machine, such as Superbmelt Jewelry Rolling Mill (picture below), it has a capacity for automatic fuel filling and lubricating system. And it can be personalized or customized. On the other hand, manual rolling mill requires manual fuel filling and lubrication, and this can slow down the process of minting coins.
Highlighted below are some great features or qualities that differentiate Superbmelt metal rolling mill from the others:
|Feature||Superbmelt Gold Sheet Rolling Machine||Other Gold Sheet Rolling Machines|
|Type||Mainly automatic||A lot of them are manual, but some automatic ones, too|
|Smoothness||Very smooth||Manual rolling mills can’t produce the same smoothness as automatic rolling machines|
|Mirror-finished design||Perfectly done||Not always producing mirror-finished design|
|Smooth-finished surface||Perfectly done||Not always making smooth-finished surface|
|Uniform sheet||Uniformly made sheet||Not often uniformly made sheet|
|Low roll loss||Yes, always||Sometimes|
|Accuracy||Very accurate||Slightly accurate|
|Method of Fueling||Automatic fuel filling||Manual fuel filling|
Some problems to avoid while rolling the sheet
Avoid these problems while rolling the gold sheet you are going to use in coin-making:
- Roll the gold sheet to the required thickness. If the sheet is too thin or thick, it may affect the quality of the coins you are making.
- Allow the sheet to be heated as required; do not mistakenly stop the sheet from being heated to the required temperature.
If you don’t do the sheet rolling well, it may affect their final shapes. So, be careful while doing this.
3.3, Obtaining a round blank and processing it
This is the third stage in gold coin minting process. The blank coins have no patterns or images on them. They must be obtained with the right shape.
If you want to get the best-shaped coins, you must make sure that you do this stage very well, because if the shape of your coins are uneven, they may be rejected in the market.
They may be considered to be fake. Many countries have different shape specifications for their coins; they want to make sure that the coins they are producing are of great standards. This makes it possible for the counterfeit coins to be easily detected in the market.
3.3.1 How to get the shape of the coin
The blank discs (which have the same shape as the coins to be produced) are obtained by punching them from the finished plates. These are practically coins without any logos, patterns, or designs embossed on them yet.
3.3.2 How to reduce gold loss during stamping
Normally, coin stamping and cutting of presses will cause some gold losses, but using Superbmelt machine the following features are built in to help reduce losses:
- The machine comes with a gas chamber that releases inert gases in the vacuum.
- This vacuum eliminates any form of porosity or shrinkage.
- More so, it prevents oxidation that can result in massive gold losses.
3.3.3 How to polish rough billets
Once the billets have been made, they may have some rough edges. So, you have to carry out edging, which is the process of sharpening the image of the coins. This indicates that the edges or periphery of the blank coins is edged using a polishing machine or coin cutting machine. After that, you can soften the blanks by annealing it.
Some problems to avoid while cutting the sheet into shapes
Pay attention to the following warnings:
- Do not use any equipment or machine that will not get you the required shapes. This may affect quality of the coins.
- Don’t use the coin-polishing machine you don’t know how to operate very well. Too much polishing can make the coin lose their physical mirror effect.
This is the last step in the coin minting process. It simply means adding images, designs, logos, and other inscriptions on the blank coins. The observe and reserve sides of the coins (the two sides) are stamped with the appropriate patterns. And the coins’ edges are milled at the same time.
3.4.1 In the past, how to make coins have patterns
Before now, people used some traditional approaches to emboss patterns on coins. Some of these age-old processes include:
Beating: They beat the patterns into the blank coins by using sharp objects that can bite into coins when pressure is applied on them.
Screw pressing: This involves using a screw that has the desired pattern already embossed on its surface. By screwing it, the pattern will be transferred to the coin.
True gas press: True gas was also used then to press the desired patterns on blank coins.
3.4.2 Hydraulic press application
Nowadays, the modern machine used for coin stamping logos or designs on blank coins uses large tonnage hydraulic coin press (300-500t), which works by applying hydraulic or fluid pressure to a cylinder that is pressed against the object being pressed.
It is important to notice that the quality and design of the mold determines the quality of the final product. This is the key to coin’s long-term preservation.
The features of Superbmelt hydraulic logo stamping machine is highlighted below:
- Adopting four-column and three-plate structure, the planar accuracy of the movable plate fish table is high, the four-axis precision linear self-lubricating guide sleeve is controlled, and the vertical accuracy is high.
- Imported high-quality hydraulic components, electrical components, low noise, high performance, stable operation
- Simple operation, pressure, stroke and closing height can be adjusted by pressing process requirements.
- Two-handed operation, with emergency stop and inch movement function, infrared hand protector, optional three-sided cover, safe and efficient.
- Press height, stroke, worktable size can be customized according to customer requirements. It can be equipped with cooling system, blowing device, pressure retaining device, pressure relay, force measuring display, PLC operating system, etc.
Some problems to avoid while embossing the coins
This is the most sensitive part of coin-making. Avoid the following problems:
- Position the coins well so that the right patterns and designs can be embossed on them. If you do not position them well, the patterns will be embossed in the wrong places on the coins.
- Strictly follow the embossing procedures. If you do not, you may end up having coins that are partially embossed.
Some important facts
If you are going to do a successful and cost-efficient coin minting, you need to pay attention to the following important facts:
- Automation: It is advisable that you use a coin-minting setup that is automated, from casting gold sheet to embossing the coins with the appropriate patterns. Automation will save you money that should have gone into hiring more workers. More so, you will be able to reduce errors attributed to humans. In other words, you will be able to smoothly run the operations of your minting press. Most of Superbmelt machines are automated or can be automated.
- Protections: You should pay attention to the kind of coin-making machines you are buying. If they do not have the necessary protections, you may end up spending a lot of money of their repairs within a short time after purchasing them. Superbmelt coin-machines come with some important protections such as:
- Detection of overvoltage.
- Quick detection of a shortage of water.
- Operating under green technology that produces smokeless operation that do not pollute environment. In this case, the machines are also protected from being destroyed by pollutants such as smokes, dust, and others.
- It is possible to detect if the machines are not working as programmed or operated.
Coin-making Machines: A Buying Guide
It is important that you buy great coin-making machines if you want to make good coins. As explained in this book, you will need the following machines to successfully make your gold coins:
- A vacuum gold bar casting machine, jewelry vacuum casting machines, jewelry continuous casting machine, or gold bar making machine.
- A Gold sheet rolling machine.
- A coin polishing machine.
- And, a hydraulic logo stamping machine.
When selecting an equipment or a machine for your gold-coin-making processes, you need to identify if the machine possesses the following helpful features:
Is coin minting line environmentally friendly?
You don’t want to invest your money on equipment that will cause plenty of pollution in the location where you operate. Pollution from the machines may affect air, water, land, and everywhere else. If you pollute the air or water in the city or town where your business is located, you may find it difficult to win the trust of the people and health authorities in that location.
Is coin minting line automated?
Most machines are automated today, meaning that they can be operated by simply pressing a button. The good thing about automated machines is that they help companies reduce the number of workers they needed. If your gold coin-making machine is automated, you may need just one or two workers to do the same job more than ten people would have done if it were a traditional method of making gold coins.
Does the machine provide material(gold/silver) protection?
Some of the protection required when manufacturing gold coins include anti-oxidation, anti-shrinkage, and temperature control. If your gold-coin-making machine or silver coin making machine does not have any of the protection listed above, you may end up paying more to safeguard your gold coins from being oxidized, shrunk, or exposed to unnecessary temperatures.
How compatible is your gold-coin-making machine?
Does it work in collaboration with other equipment or electrical appliances? Most gold-coin-making machines are not standalones; they are connected to other equipment before they can complete their duties. So, make sure the equipment you are buying can work smoothly with other types of machines or devices.
How to maintain the mint production line?
Is it cheap to maintain your metal-coin-making machines? If you had bought your equipment new, you may have the hope of using them for a long time. But sometimes gold coin manufacturers who cannot afford new machines may choose to purchase a used one. In this case, are you aware that your second-hand machines can work for some time, a long time before breaking down? Spending money on continuous maintenance will make your gold-coin-making business to be more expensive than the average cost of running such a business.
How to make the workplace safe？
Are you investing your money on buying gold-coin-making machines that won’t harm your workers? Some foundries are more dangerous than hell because they are constantly exposed to heat from the furnaces. Sometimes, a thick plume of smokes is produced and may cause breathing problem for these workers. Another issue with the traditional method of making gold coins is that the environment is not enclosed, and pollutions may reach the air or other parts of the ecosystem from there. If your workplace is not safe, and your machines cause bodily harm to your workers, you may be required to pay a lot on occupational insurance as well as taking care of your wounded workers.
Is your equipment made by a well-known high-quality machine manufacturer?
This refers to the issue of brand: Some companies have brands that have survived several tests and years of using. Their products are reliable, durable, and can work under different conditions. You can also judge a quality gold-coin-making equipment manufacturer by the number of good products they have. This shows that they have many customers all over the world and doing everything to improve their already standardized machines. When you buy machines or equipment from a famous and efficient brand, you will have a lot to save against regular maintenance, repairs, and so on, because they won’t break down every now and then. A good manufacturer will offer customized maintenance for some time; so, choose equipment-making company wisely.
Does the manufacturer of the equipment offer manuals or guides that are easy to understand?
When you are buying a new equipment, chances are that you won’t know how to use it perfectly. And when you are lucky to have a good instruction manual provided by the equipment manufacturer, that will help you overcome the initial fear of trying a new machine. You will be able to concentrate only on how to gainfully use the equipment to advance your gold-making business.
How long is the warranty period of the production line
A good gold-coin-making machine company should be able to give you, at least, one-year warranty. This indicates that if your equipment suddenly develops any mechanical faults within a year, you can return it for free repair. In some cases, you may be able to get an entirely new machine to replace the one you had purchased. Avoid equipment manufacturers that offer less than a year of warranty, because you can never be certain that a new machine you purchased won’t have a mechanic problem any time. You can inquire from your targeted manufacturers before committing to the purchase agreement.
How does Superbmelt’s vacuum casting process solve the problems caused by the casting process
There is plenty of information in this book that will help you improve your business of making gold coins.
So, these are the main four lessons you can learn from this book: Equipment, Material, Process, and Expertise.
Check out chapter 4 for all the necessary information about buying the most appropriate coin making machines for sale. These could be gold press machine or silver making machine.
The main material discussed in this book is gold, even though other noble metals such as silver, platinum, and so on can be used to make coins. If you want to have a good gold product, you must pay attention to the quality of the material used.
For instance, which Karat are you using? Is it an original gold or imitation? It is also important how you handle the gold materials. Some procedures may expose the gold to oxidation (even though gold doesn’t easily oxidize), shrinkage (any metal put under unnecessary pressure will shrink), and loss of material (if you apply wrong procedure, you may end up losing a chunk of your gold in the process).
So, you can see that it is very important to pay attention to the material. Gold is an expensive noble metal and losing some parts of it may not only make your process expensive, but also cost you some customers, if you are a commercial jewelry-maker or goldsmith. On top of this, how did you obtain your gold? What source or country does it come from? The quality of gold may also depend on its source.
However, this has not been absolutely proved by the experts or gold associations worldwide. And, what procedures are you using to polish your gold?
The processes are the methods or techniques used in producing or manufacturing your gold coins. Until now, gold-coin manufacturers have relied only on the traditional method of making gold coins.
But the invention of new, gold-coin-making machines and technologies have made the whole processes easier and faster. And it will be useful for your business to learn these new techniques in order to improve your gold products or gold materials.
Nowadays, there are emphases on coin making press processes that are environmentally friendly. You need to ask yourself these essential questions: Are my gold-coin-making processes good for the environment?
Are they producing little or no pollutants to the environment? Are they healthy and won’t affect the health of my workers or employees? Are the processes I use cost-effective? Are they sustainable?
If you can provide positive answers to the questions, the chances are that you are applying modern methods of making gold coins. And the best way to continue this is to use equipment that are absolutely environmentally friendly.
One great advantage of buying equipment from famous or well-known coin machine manufacturers is to have the opportunity of learning new things or concepts from them.
They will be willing to easily pass some expertise that you need to operate the machine to you. On most occasion, this high level gold-coin-making education is offered to customers as complementary free services.
You can also increase your expertise in coin making equipment by joining some regional gold associations and meetings. You will be able to learn from each other as members of the same organization.
The truth is that gold-coin-making techniques are improved upon from time to time, and the best way to be abreast of such timely information is to be part of a group or association that have access to the latest concepts in gold-making. It is through this approach that you will be able to maintain quality in your gold-making processes.