One of the most important alloys that have been with humans since the beginning of time is brass. An alloy with copper and zinc as its principal elements, brass has found a lot of uses. It is because of this very useful nature of brass that ensures it still remains with us. Of late, there has been renewed interest in the exact composition of brass. This is in relation to the presence of lead as one of the components of brass.
So does brass contain lead?
The answer to that question is yes and no. There are different types of brass. But, there are some other useful explanations for this answer. These explanations are going to be provided in the sections of this piece. Copper and zinc are the main metals used in the production of brass, but lead is also added sometimes.
Types Of Brass
Based on the topic of this article, brass can be divided into two main categories. These are leaded brass and unleaded brass.
Other Types Of Brass
Brass is not categorized only on the basis of its lead content alone. There are some other classifications of brass and they will be discussed in the section below.
Free Machining Brass
This type of brass has a lot of lead in it. For this reason, it is very soft and very malleable to work with. Another name for it is 360 brass and it is used in several machine processes.
This type of brass is very easy to work with. For machinability, it is also an outstanding type. For this reason, it is used in the production of all kinds of cylindrical objects. These include pipes and tubes.
This got its name from the hue. When it comes to strength, it is on the high end. This type of brass has a lower level of zinc when compared with other types of brass.
Some are able to infer the meaning from its name. This type of brass is built to withstand corrosion. For this reason, it has found a lot of use in naval engineering.
In this sector, it has another name and that is 464 brass. It is able to have this incredible strength against corrosion because of the addition of another metal. That metal is tin and only a very tiny part is needed, usually one percent.
Some other people refer to this as yellow brass. It is one of the most popular types of brass. It is an excellent material when it comes to the production of metal for shell casings. It comes out as vast sheets. These sheets are then sent for further processing and come out in different shapes.
Another name by which cartridge brass goes is known as 260 brass. You would have seen it in movies where a lot of arms and ammunition were used.
Why Is Lead Added To Brass?
Now that it has been established that lead is added to brass, there is a question that will follow. This question has to do with why lead itself is even added to brass in the first place. One of the most important reasons why lead is added to brass is to make it more ideal for machine operations.
When the brass is needed for machining work, then some lead is added. This explains why leaded brass is utilized in machine works. That is also the reason why a significant part of leaded brass is made in the shape of cylindrical rods.
When lead is added, the brass takes upon a greater degree of softness. That way, it becomes very easy for the machinists to handle in their workshops. This is also called increasing the malleability of the metal. The more malleable a type of metal is, the softer it is. That means the easier it is to work with.
What Is Lead?
Some might be wondering what exactly is lead. Well, lead is a metallic element. It is heavier than many of the other commonly-used substances. The extraction of lead is from ores. Galena is the ore of lead and it also contains silver.
Lead has a lot of uses and applications. This because of its physical and chemical characteristics. But there is a drawback to lead. This is because it is toxic to the human body. This has led many governments across the globe to enacting several laws. The laws are to tackle the consumption of lead.
What Is Lead-Free Brass?
Of late, there has been a lot of controversy over the safety of lead used in plumbing materials. For this reason, the United States government has enacted laws like the Federal Safe Drinking Water Act. The aim is to slash the amount of lead in pipes, valves, and fittings. All these convey the water we drink.
According to this Act, the highest content of weight lead in plumbing products is going to be 0.25%. This is 32 times less than what obtained in the past. That was how the concept of lead-free brass became more prominent.
Lead-free brass is quite different from conventional brass. In this type of brass, the lead is replaced with some other materials. These can be bismuth, silicon or mixed copper alloys. The brass still retains its machinability and excellent pressure tightness. In fact, you cannot distinguish the two based on physical appearance alone. Both look exactly the same.
But, it is important to state one thing at this juncture. Lead-free brass has its parts replaced by other materials like silicon and bismuth. But it can actually still contain lead. But, the lead is going to be in trace amounts. Also, the lead composition cannot be beyond 0.25% stated by law.
Interesting Information On Brass As An Alloy
Brass is one very useful metallic alloy. By changing the percentages of the copper and zinc that go into the production, the hardness or softness of brass can be modified. In some other cases, other metals can also be added. These include lead, which is the subject of this topic.
Other metals that are also added to the alloy include aluminum and arsenic. Apart from making the brass more machinable, brass has other metallic alloys for another reason. This is to slow down the corrosion of the metal.
It is possible to change the characteristics of brass. This is by including different metals to it. One can change the color, strength, malleability or even durability. All these are by tweaking the components. Here are good illustrations:
- When a higher level of softness is desired in brass, all that is needed is for some lead to be included.
- In a case where there is the need for a change in the color of brass, another metal can be added. The metal, in this case, is manganese. Even a minuscule amount of manganese can change the color of brass. It can transform it from its usual inviting and shiny golden hue to a brownish color in appearance.
If a machinist wants the brass to have a more glistening appearance, nickel is often
- To increase the strength and hardness of brass, the metal of choice for addition is often tin.
- When the stability of brass is to be increased, then an element like arsenic can do a good job.
Applications Of Brass
A point was hinted at in the very first section of this piece. Brass is one of the most commonly used metal alloys known to humanity. This is because it has a vast array of uses and applications. All these are both aesthetic and functional in nature.
Various musical instruments are made from brass. Common examples include trumpets, tubas, trombones, and horns. All these brass musical instruments even have a name that is very descriptive. The name here is brass section. This is the name they are referred to as in an orchestra.
For those who are observant, all these musical instruments are very shiny. This made some think they are gold-plated. It is not gold but brass. Brass is used for these highly-folded instruments because of its malleability. These instruments have different shapes. Because brass is very easy to work with, it is the ideal choice.
Another area where brass has found immense use is in plumbing and construction. The reason for this is because brass is good when it comes to resisting corrosion. So, it is common to see plumbing or building components and items all made out of brass.
The military is another area where brass is in high demand. The casings of shells are almost always made from brass. But this is not because of its resistance to corrosion. There is another reason for the use of brass in this area and that is as a result of its low level of friction.
The production of precision instruments is another area where brass is a beloved alloy. In this sector, the products come in different shapes. Clocks are examples in this regard. Once again, few metals like brass can be easy to work with like brass.