The world of metals is a wide-ranging, complicated place. With our “Materials Focus” series, we aim to shed some light on different materials that we commonly use. Some of the topics we’ll be covering in our “Materials Focus” series include general elemental components of popular alloys, strengths and weaknesses, common uses, and photographs of parts we’ve made.

This week’s material is, Copper.

Copper

Copper is a material that has been used by many different societies across the world, for centuries. It is a natural metal that traces of can be found in a native form, (actual chunks of pure copper) but is most commonly found mixed with other elements. Original uses of copper can be traced all the way back to ancient China, and parts of the Middle East.

However, what makes copper such a common commodity today is its malleability, and its high conductibility for heat and electricity, making it a widely used material in the HVAC and building industries. Pure copper is very expensive, and is unfortunately a common target in HVAC related thefts, that are turned around and sold to unknowing scrap companies. There are numerous amounts of copper alloys, and even some secondary processes that aim at making copper products more affordable and usable.

Copper Alloys

The list of copper alloys is quite extensive. So much so that common metal names such as bronze, and brass are actually both copper alloys. Thus, all bronze and brass alloys are still really alloys of copper. Adding the alloys that are made with combining precious metals gold and silver, the list is too long to go into great detail for this blog.

To keep things relatively simple, yet informative, the main difference in brass and bronze is what is mixed in with the copper. Brass is primarily a mix of copper and zinc, whereas bronze is a mix of copper and typically tin, but can also be aluminum or silicon. As you get into the alloys of each respective material, there are additional metals that enter the mix, but the zinc and tin/aluminum/silicon are the commonly present mixtures that make each alloy.

While the alloys have different contents and uses, the price of each doesn’t necessarily drop dramatically and they still have a high malleability compared to steel. So how does one go about making mass quantities of copper parts without breaking the bank, and getting the rigidness of steel? This is where a process referred to as “copper clad” comes into play.

Copper Clad Material

Copper clad material is a bi-metal product that is made primarily of regular steel, with a coating of copper on top and at the bottom of the steel. Copper clad material has greatly benefited the wire, electrical, and plumbing industries because of its capability to posses the conductivity of copper, yet at the same time still have the tensile strength of steel. While copper clad material does come with a lower price tag of a similar, pure copper product would, it is still significantly higher than regular steel.

In our world, copper clad pipe straps are required when copper piping comes into play. Regular steel pipe straps would eventually erode copper piping, however with copper clad products, plumbers and electricians are capable of keeping the rigidity of steel for the main body and putting copper to copper eliminating any material issues that would arise.

We hope this month long series on materials has been helpful for you to understand the different uses of the materials we commonly use. Feel free to leave any unanswered questions below in the comments section. Next week, we’ll start to dive into the world of production dies. We’ll discuss the different styles of dies, along with different components that are required to run dies as efficiently as possible.

The world of metals is a wide-ranging, complicated place. With our “Materials Focus” series, we aim to shed some light on different materials that we commonly use. Some of the topics we’ll be covering in our “Materials Focus” series include general elemental components of popular alloys, strengths and weaknesses, common uses, and photographs of parts we’ve made.

This week’s material is, brass.

Brass

General Information

Brass is one of the softer, and visibly speaking, visually pleasing metals a machine shop can work with. Brass is used for a wide variety of purposes ranging from musical instruments, to nautical products. While it is not the toughest of metals, brass has many uses and different forms. Brass itself is actually a copper alloy, as depending on the type of brass, the copper content ranges from 53.5% to 86%. While copper is the majority element that makes up brass, the change in zinc and lead levels significantly vary the properties of brass and how it is used.

Lead and Zinc levels in Brass

Zinc and lead additions are what typically make the biggest difference between the brass alloys. Higher levels of zinc make brass a harder material, and also helps protect it against corrosion. 464 brass, also known as naval brass, is an example of a high zinc leveled brass at roughly 37-39% zinc. A small amount of tin is also mixed in to help fight corrosion.

Lead is a naturally soft metal, and when it’s mixed with alloys it helps create softer, and more machinable metals. 360 brass, or machining brass, has the highest amount of lead of all the brass alloys. 360 brass is great for machining purposes, however using it as a forming piece does not bode well, as it is the most malleable of the brass alloys.

360 Brass

The most common brass you’ll see in a machine shop is 360 brass. This version of brass is high in zinc levels, but also contains the most lead levels of all the brass types (keep in mind that while 360 brass may have highest amount of lead content of all versions of brass, lead only accounts for roughly 2% to 3.5%). 360 brass is used for many different purposes, including decorative pieces and even functional pieces such as the hammer in the picture below. 360 brass is great for tool and die working hammers as it allows for the regular function of a hammer, yet does not dent or damage the harder tool steel.

While brass is more expensive than standard steel, it still is a widely used, and very important material. Whether it be sidings on a boat, decorative pieces to lighting fixtures, or die shop hammers, brass is found in every corner of the world in many different functions.

The world of metals is a wide-ranging, complicated place. With our “Materials Focus” series, we aim to shed some light on different materials that we commonly use. Some of the topics we’ll be covering in our “Materials Focus” series include general elemental components of popular alloys, strengths and weaknesses, common uses, and photographs of parts we’ve made.

This week’s material is, aluminum.

Aluminum

General Information

Aluminum is a highly flexible and commonly used material for machining purposes. There are many great characteristics of aluminum that make it one of the more commonly used materials in manufacturing, across many different sectors of business. Aluminum is a relatively soft and light metal, making it a highly form-able and weldable material. Along with its ease of use, aluminum is also highly resistant to corrosion.

These positive attributes aluminum possess are main reasons as to why aluminum is found through out all industries. Common places you will see aluminum being used vary from the food processing, marine applications, railroad, furniture bracketing, and outdoor construction projects.

While there are many positives about aluminum, just like anything in life, there are some draw backs as well. Due to its soft nature, aluminum is not a great option when there will be a high amount of potential stress to the product. Aluminum also has a naturally high reflective rate, which can make laser cutting aluminum difficult and add extra wear to the laser cutter.

6061 Aluminum

There are over thirty-five aluminum alloys that are used to manufacture parts, however, there are ten common alloys most used. You may find a list of the ten common alloys here.

The alloy we find ourselves using the most is the 6061 alloy. The 6061 alloy is highly machinable, and keeps to form well when heat treated is necessary. 6061 is 97.9 % aluminum, while the rest is made up of 1% magnesium, .6% silicon, .25% copper, and .25% chromium.

With the mixes of other materials, 6061 aluminum is a harder material than 1100 aluminum, also known as “commercially pure aluminum.” Here are some of the strength differences of the two materials:

Strength Measurement (value)	1100 Commercially Pure Aluminum	6061 Alloy Aluminum
Tensile Strength (psi)	13,000	18,000
Yield Strength (psi)	5,000	8,000
Hardness (Rockwell)	35 to 55	60 to 75
Shear Strength (psi)	9,000	12,000
Fatigue Limit (psi)	5,000	9,000

The information in this table was derived from, “Metals Handbook, 8th Edition” published by The American Society for Metals, pages 936-946.

The world of metals is a wide-ranging, complicated place. With our “Materials Focus” series, we aim to shed some light on different materials that we commonly use. Some of the topics we’ll be covering in our “Materials Focus” series include general elemental components of popular alloys, strengths and weaknesses, common uses, and photographs of parts we’ve made.

This week’s material is, Steel.

Steel

General Information

Steel is one of the most important materials of current day existence. Every where one looks, there are products made with steel of all different alloys in every facet of life. From the machines we operate, to the buildings we work in, to the cooking utensils we eat with, some form of steel is present. While we cannot cover all aspects and alloys of steel, we’ll focus on the general processing of steel, the difference between plates, bars, and coils of steel, and the 4140 alloy.

Steel Processing

The process to manufacture steel has many steps, and variations depending on the type and form of steel the manufacturer is producing. However, the general steps to processing steel are similar:

• All raw materials (coke, iron ore, and lime) are first combined in a blast furnace that melts all of the ingredients into a liquid iron substance. These blast furnaces can reach up to 2,300 degree Fahrenheit.
• The liquid iron is then sent either to an Electric Arc Furnace, or a Basic Oxygen Steelmaking process. Both processes mix scrap metal into the liquid iron to lower the amount of carbon to 0-1.5% of the material. This is the first major step of producing steel, as the liquid iron is typically 4-4.5% total body weight of carbon, which is too brittle of a substance to machine.
• Secondary processes and additions are made to improve or add elements to the mixture in order to produce desired alloys.
• Once all ingredients have been added, the mixture is cast into billets, blooms, ignots, or slabs.
• The resulting billets, blooms, ignots, and slabs are then formed into the product that is sold to manufacturers. These products include, sheet metal, bar stalk, and coiled metal.

Sheets, Bars, and Coils

Three of the main forms that steel processors create, that we mostly work with, are sheet metal, bar stalk, and coils.

• Sheet metal is self explanatory in its form, it’s simply rectangular or square sheets of metal. Depending on the gauge and dimensions of the sheet metal, they can be quite heavy. Sheet metal is either hot or cold rolled from slabs of raw material. Sheet metal is great for laser cutting projects, or any sort of paneling or automotive applications.
• Steel coils are used in stamping operations, especially when high speed production is desired. Steel coils allow for the manufacturer to load the coil on a reel or un-coiler. The running speed varies based on the feeder, and die speed.


A skid of steel coils. Steel coil is used in punch press operations

• Bar stalk comes in a wide variety of dimensions. Some bar stalk is closer to a cube shape, where all three dimensions are equal or close to equal, where as some bar stalk is alomst small sections of sheet metal. The dimensions of bar stalk required depend on what the final part’s dimensions will be, as limiting scrap metal is key to any machine shop operation. Bar stalk is usually derived from billets as they tend to posses the flexibility for thickness bar stalk requires. Steel bar stalk is best used for machining projects. The 4140 steel alloy is commonly used in machining situations.

4140 Steel Alloy

There are nine classifications of steel alloys. The beginning numbers are determined by the amounts of alternative elements within that steel. These steel grades are given by the AISI and SAE, and are consistent through out the US, and the world. 4140 steel alloy falls within the Molybdenum steel grade, and possess .12 to .3% Molybdenum, .5 to .95% Chromium, and the remaining percentage Iron. 4140 steel is great for machining die components, as it’s easily machinable as annealed material, but can be hardened in multiple ways.

More Info on Steel Processing

If this hasn’t quenched your thirst for steel processing and manufacturing, a great step-by-step explanation can be found at the World Steel Association’s, “Steel University” website.