We’ve covered all popular types of materials used for CNC machines in this article. So, let us guide you through the thinking and things of CNC machining before you conduct business with any CNC machining shop.
Factors That Influence The Selection of Materials for CNC Machining
Various factors determine which CNC materials are ideal for a certain application.
The following factors should be considered before choosing the best material for your project.
Outdoors versus Indoors
An outdoor component must resist rain, UV rays, and other weather conditions. Too, such components need sturdy design elements and long-lasting material qualities.
So, an indoor component is not exposed to harsh external conditions, so a wider variety of acceptable materials is accessible.
Utilise the component’s function to narrow down the materials you might use. For instance, you should refrain from using metal materials when making toys.
Instead, a substance with low conductivity is required when producing insulation-related components.
High-strength and hard materials may appear ideal, but they need more processing time and put more strain on cutting equipment.
Every material’s dimensional tolerance impacts the manufacturing part’s correctness. Yet, dimensional tolerance may only sometimes be a crucial consideration.
If a project calls for tight tolerances, you will need specialised cutting tools for the CNC machine because tolerance has a cost.
It is less expensive to use a material with an appropriate dimensional tolerance at first rather than paying to resize the part later.
Range of Temperatures
Take into account the surroundings and the end product’s operational temperature range.
The substance must withstand the necessary working temperature and any anticipated thermal fluctuations. Temperature variations cause a lot of materials to expand.
Cutting tools used in CNC machining operations, like CNC milling, produce heat. The component material absorbs the heat from this source.
Both chemical and high-temperature resistance are significant. For instance, a CNC-machined component for use in a lab or other reactive environment must be resistant.
Using metal materials in an acidic environment is never a good idea.
Concentrate on the material’s corrosion resistance properties for environments with high humidity. Materials with weak corrosion resistance can rust and deteriorate.
Does the project call for using high-strength metals in a humid environment? Consider corrosion-resistant.
Costs of materials almost always have an impact on material choice. The majority of product teams seek to maximise desired material attributes and performance while spending the least amount of money possible when choosing a material.
When it comes to CNC machining, material costs are particularly crucial because this technique leaves behind a sizable amount of scrap material.
Some materials, including speciality metals, are quite expensive, which could have a significant effect on the project’s cost-efficiency when taking scrap material output into account.
Before making any decisions, engineers should thoroughly assess their financial situation.
Select a material that offers a high-quality surface finish if aesthetics are important. For instance, a smooth glossy or matte surface finish can be applied to a metal surface.
Unfortunately, many materials made of plastic do not have this characteristic.
Cost of Raw Materials
The final decisive factor in selecting the ideal material for CNC machining is the price. Have you got a tight project budget?
Have a go through the list of materials to consider, always look for materials with low cost and high machinability.
Strength and Durability
The part must undergo a reliable manufacturing procedure to endure the specified lifespan. Thus, consider the application’s needs for strength and durability and select a material that fits them. Consider the following elements:
Tensile Strength: Tensile strength is the tension a material can withstand before failing.
Wear resistance: Wear resistance is abrasion resistance, wear and tear throughout a lifecycle.
Endurance Power: The amount of stress that a thing can withstand. High endurance strength characterises an impact-resistant material.
Leading Materials for CNC Machining
Following is a list of materials that are used for CNC machining:
Aluminium alloys are lightweight and easy to process in large quantities. They have excellent thermal and electrical conductivity. Additionally, they are rust-proof.
All-purpose aluminium alloy 6061 is frequently used for CNC machining. Automobiles, bicycles, sporting goods, and other leisure products frequently contain them.
Aluminium is very machinable, although it can be more expensive than other metals. In addition, it doesn’t hold up well when exposed to chemicals or seawater.
Aluminium 7075 is an improvement above 6061. It is the strongest commercially available aluminium alloy.
It is perfect for aerospace frames and high-performance recreational equipment.
The aerospace, automobile, cookware, medical, and consumer product industries frequently use aluminium alloys.
Besides, a common material for casting or brazing is aluminium. The drawback of using aluminium is that it is difficult to weld.
After machining, aluminium CNC projects could also require extra post-processing or finishing.
Learn More: 6061 Vs. 7075 Aluminum, Which One Is Better?
Today’s stainless steel industry offers a wide variety of alloys. 304, 316, 416, and 17-4 PH are common grades for CNC machining.
Strong materials with a protective oxide coating t make stainless steel ideal for tough situations.
The alloying components that make up the different stainless steel grades cause them to vary.
For instance, molybdenum is added to 316 stainless steel to boost corrosion resistance. Sulphur increases the machinability of 303 stainless steel.
Many components use stainless steel alloys, including consumer goods and industrial applications.
Other components include large machinery, medical equipment, appliances, aerospace, military, and automobiles.
Additionally, stainless steel is used for parts that need to be exceptionally strong.
Few grades of stainless steel are easier to mill than others. Although all are machinable stainless steel CNC machining is a used procedure.
Nylon, a thermoplastic material with many uses and minimal friction, is widely used instead of metal in CNC-produced parts.
Even though it is strong, rigid, impact-resistant, and chemical-resistant, this material is elastic.
In addition, since nylon responds well to additions and fillers, engineers can change it to get the desired properties.
Nylon is used in various products. Including electrical moulding, fabric, gears, food packaging, and automobile parts.
Unfortunately, nylon readily absorbs moisture, which may adversely affect a part’s structural stability.
Copper is a superior thermal and electrical conductor. Silver is the only metal that performs better than copper for thermal or electrical applications.
However, copper is challenging to CNC mill due to its high malleability at lower temperatures and strong flexibility.
The more pure copper alloy is 101. It performs well in applications that call for high flexibility and impact resistance.
However, it is less effective in resisting corrosion. Wiring, electrical parts, including busbars, and electronic components can all be made with Copper 101.
The greatest electrical/thermal conductivity of any copper alloy is provided by copper alloy 110, which is somewhat less pure. As a result, it also has greater corrosion resistance.
As a copper and zinc alloy, brass shares several characteristics with copper. Brass is strong and simple to machine.
Additionally, this alloy has a low coefficient of friction. It is corrosion-resistant and conductive.
Plumbing, electrical, aesthetic, and medical applications are just a few of the many uses for brass.
The most machinable brass alloy is 360 Brass, often known as free-machining brass due to its high machinability. Besides, it has outstanding strength and corrosion resistance.
Many sectors have been transformed by titanium. It has also supplied answers to some of the most difficult problems in the manufacturing sector.
Titanium alloys are durable, robust, comparatively light, and corrosion-resistant. Moreover, as the noblest metal, titanium performs in hostile situations where other metals falter.
Once titanium was found to be biocompatible, the medical industry jumped in with its use. Medical gadgets and implanted parts like screws or devices are now frequently made of titanium alloys.
These advanced alloys are also widely used in the aerospace, industrial, and military fields.
Aluminium is two times as strong as titanium, which is, but just more dense. With products like lightweight golf clubs, titanium is also well-liked in the consumer goods sector.
Guess you like Titanium Vs. Stainless Steel, What Is The Difference?
Polymers comprise most of the vast synthetic and semi-synthetic materials known as plastics.
Excellent CNC-machined plastic components are available in a wide range of configurations.
Certain polymers, such as HDPE, are moisture-resistant, insulating, and chemical-resistant. Chemical and friction wear are both resistant to nylon.
PEEK is a lightweight material that resists chemicals, wear, and moisture.
Even as a CNC machining material substitute for the majority of soft metals, PEEK can be used.
Polycarbonate is one of the polymers most used in machining because of its great heat and impact resistance.
Due to their low cost and lightweight, CNC-machined plastics are widely used.
Applications include bearings, containments that can withstand chemicals, laboratory apparatus, screws, electrical parts, and medical devices.
Carbon and Alloy Steel
One of the cheapest and most widely utilised steel alloys is low-carbon steel.
As the name suggests, carbon is used as an alloying element in steels, coming in second behind iron in percentage composition.
Low-carbon steels are more malleable and weldable and have a lower carbon content (0.05-0.25%);
However, unlike high-carbon steels, they cannot easily be heat-treated to increase hardness. But, low-carbon steels can be CNC machined rather.
Motor shafts, pump shafts, pins, sprockets, spindles, fixtures, mounting plates, and hobby parts are made of alloys like 1018 steel.
A robust alternative that can be induction hardened is medium carbon steel. Besides, heavy-duty applications like bolts, studs, and other fasteners are ideal for alloys like AISI 1045 medium carbon steel.
So, With up to 8% alloying elements, alloy steel is more ductile, heat resistant, corrosion resistant, and weldable than carbon steel.
So, it is utilised in appliances, cars, cutlery, kitchenware, and industrial uses.
General Advice for CNC Milling Specific Materials
What you’re trying to manufacture determines which CNC machining materials to employ for your item.
However, the following general advice might serve as a quick CNC materials guide:
Don’t assume that metals are your best option; consider non-metallic materials.
Non-metallic materials, such as foam, can be moulded into many shapes.
They have gained popularity since they are lightweight and strong. During cutting, non-metals also hold onto tiny details.
Recognise the distinctions between the various types of foam: stiff foam and carving foam have different uses.
Both rigid and carving foam are lightweight yet strong materials.
However, carving foam is frequently used as insulation for mould prototypes.
At the same time, rigid foam is appropriate for pieces that focus on structural integrity and stability.
Phenolics are fantastic possibilities when you need to follow particular rules for projects.
Learn more about various plastics: You can pick from many different plastics. Acetal is frequently used to replace bushings and bearings.
PVDF, or polyvinylidene fluoride polymer, is used as electrical wiring insulation. Medical biomaterials can use UHMW, including knee, hip, and spine replacement devices.
These are only a handful of the countless applications that plastics can be used for.
Get Guidance on Choosing Materials from Experts
This is a partial list, but it is evident that CNC machining is a highly versatile production technique.
Finding the perfect equilibrium between time, money, and quality can be difficult.
Working with a reliable on-demand manufacturing partner like us makes material selection simple.
Our manufacturing professionals have years of experience in design and material selection.
Besides, we have professionals for guiding product teams through product development and production. Contact us to begin creating something extraordinary with us.
Which material requires the most effort to CNC-machine?
Copper can be challenging to machine and demands specialised manufacturing techniques.
What material is the most machinable?
Because of this, steel has the best machinability when it contains roughly 0.20% carbon. Besides, steel is alloyed with chromium, molybdenum, and other metals to increase its strength.