Getting a good surface finishing with CNC machining is very important. This is especially true for parts that you will use, and parts used to make molds. CNC machining was a big hit with manufacturing clients as it was a solid and quick way to make things. The process can produce parts with very tight tolerances.

Some parts are made of metal or plastic that have been milled and machined with rough edges. A problem with this is easy to fix. Finishing is needed for some end-use or molding applications using these materials.

You can use post-processing procedures to get the desired finish on CNC machined parts. The CNC machining surface finishing is important in this case. Also, your products have a high standard of quality on the surface. This is essential if you want to make sure that even your machined part is as good as it can be. Step Rapid can provide the data you need.

The Importance of CNC Machining Surface Finishing for Machined Parts!

How they look isn’t the only consideration when it comes to surface coatings. Instead, they are used for a slew of other vital functions.

The following are some of the advantages of CNC machining finishes:

It makes the metal more resistant to corrosion.

Corrosion is a common cause of damage to metal parts and their surfaces. If a component has rust on its metal surface, it will not be as good as it should be. Corrosion resistance is the main goal of most surface finish samples for metal. The metal is well-protected by a good surface finish from the machine. As a result, it won’t break down as quickly.

It adds to its visual appeal.

Appearance can be just as important to some people as how well the product works because people see what they get. Metal surface treatments will help your CNC machined parts look their best.

It speeds up the production process.

A good machining surface finish will make it much easier to make things. For example, a surface that has been sanded or brushed is more likely to stick to paints. This helps to ease the stress of the manufacturer.

Surface finishes on parts made by a CNC machine:

• Enhances the metal conductivity
• Boosts wear resistance
• Reduces the effects of friction on the metal
• Improves strength materials
• Protects metal from chemical
• It shields the metal from chemical attacks.
• Improves the metal rust-resistance property.

Determining the Surface Finishing You Need with CNC Machining!

A professional service like Step Rapid can help you with CNC Machining, and they can help you with a variety of surface finishes. These finishes are meant to meet the needs of different applications. There is no matter what kind of product you buy. The prototype, mold, and other parts you get will have the best finishes.

Anodizing Surface Finishing

Because of the way that metal parts are made, anodizing makes the surface of them look like ceramic. This process makes things that are resistant to corrosion and wear. The anodic coating that is put on after the electrochemical process is also non-conductive. This means that it is important to cover up parts of the part while it is being anodized if it needs to be conductive.

You can anodize parts made by a CNC machine in two ways. This is Anodizing Type II that succeeds Anodizing Type I. It’s an anodizing process that most people use here. It helps to make coatings that are even and resistant to rust. This type lets you change the color of your parts. People who make things like this call it “decorative anodizing.”

The third type of anodizing is called type III, and it is the second type. As you might have guessed, this is called Hardcoat Anodizing. This type of coating makes the metal very thick. This way, you can be sure that you’ll get a high-density part that is resistant to corrosion and wear.

The main benefit of anodizing CNC machined parts is that they look better. The dye can come in different colors and last a long time. Use anodizing to make parts for engineering. It is also important to note that anodizing can only be used on parts made of aluminum or titanium.

Powder Coating

A very thin layer of dried polymer powder is applied to the item you have manufactured during the powder-coating process. This method makes the metal made with a CNC machine more durable and robust. Manufacturers put a lot of powder coating on parts to make them more stable. However, this could change the dimensions of the finished product.

Powder coating can be used on any metal that can be machined. It also lets people choose from a wide range of color finishes. Many manufacturers also use bead blasting as a post-process to get a smoother finish. It’s good for things that people will use.

As-Milled Surface Finishing

This surface finish from a CNC machine does not need extra work. CNC machining can make up to 0.025 mm-tight parts. As a result, the item will be left in its machining state. Pieces that have been machined as-is have the best dimensional perfection.

Milled parts are going to be rough. They may also still have tool marks on their surface, which means they won’t be completely smooth. It takes about 3.2 m for an as-milled part’s surface roughness (Ra) to get to that level. However, more smoothing and polishing can make the machined texture less noticeable.

An “as-milled standard” surface finish that doesn’t need to be smoothed or polished should not cost more to make. Because of this, it is the most cost-effective way to finish a machine’s surface. It’s best to use an as-milled finish on prototypes, jigs, and fixtures that need to be made.

Passivation

It is a chemical process that involves a lot of different steps. This CNC surface finish makes metal parts more resistant to corrosion. If there are any “passive layers” on the surface of the metal, this method can help them work better together.

There are a lot of different types of passivation, like these:

1. Tank Immersion: This method helps to make the finish on CNC machined metal surfaces more uniform, so they look the same. This makes the metal less likely to rust or wear out when it does this.
2. Gel Application: This treatment is done by hand. Gels are brushed onto the metals’ surfaces. It is the best way to get rid of welding spots and other small parts of the metal.
3. Circulation: It involves moving chemical solutions through pipes.
4. Spray Application: This is the best way to treat metal on-site. A special type of spray is used to change the chemistry of a layer that isn’t moving.

Bead Blasting

Bead blasting is when small spheres of media are shot at the surface of a CNC machined part with compressed air. These may be glass beads or other materials. When bead blasting is done, the result is usually a uniformly smooth surface with either a matte or satin finish.

This process uses small beads to remove small amounts of material from the surface of the machined part one at a time. Because of this, it is possible that the post-processing could change the part’s size. This could, however, have a minimal effect on your body. Bead blasting is mainly used for things that look good and for products that need to look good.

CNC Machining Surface Finishing: A General Rule of Thumb!

Some simple tips can help you choose the right CNC finishing for your product. There is no need to follow them by letter.

The general rule of thumb comes from our experience, and they are as follows:

A finish called as-milled is recommended for parts having tight tolerances. They are most useful when looks aren’t the main thing.

This type of anodizing will add a very thin layer of protection to parts made of titanium and aluminum, making them more durable. This layer of protection is also quite appealing.

Use Type III anodizing on metals that are used in engineering. In this case, the metals need to have a very hard surface and be able to withstand being worn down.

For high-impact strength, you need powder coating or if you want to finish components that do not support anodizing.

Factors to Consider When Selecting a CNC Machining Surface Finishing!

Finishing a part with a CNC machine is a very important way to make sure it looks, feels, and works well. Knowing that you can pick the best finish for your part is essential. Here are some things to think about to make sure you choose the right one right away:

1) The Product Application

Parts are subjected to various environmental conditions like heat, UV light, vibrations, moisture, etc. Considering who and what the product is for will help you in deciding. Metals that are going to be outside and exposed to a lot of things need to have a standard machining surface finish that makes them harder. The finish you choose should also make the metal and wear more durable. Parts used in construction will put less emphasis on how they look. Durability is often the main focus.

2) Durability Issues

You need to think about how long you want your product to last before you start making it. Durability is an important part of making things. The raw material is essential, but you can’t forget about the surface finish. Making your finished product more valuable means making it last longer. You should choose the right finish for that.

3) Connection Between the Metal Surface Finish and the Raw Material

The polishing of some materials is hard. It may be hard to anodize some surfaces, and some paints may not stick well to certain types of material. This means that when making a design, take CNC finishing into account at the beginning of the process. If you use a CNC machine to make something, you should not decide on the surface finish at the last minute. Make sure your surface finish is compatible with the raw materials you’re working with before working on your project.

4) The Component’s Dimensions

One thing to keep in mind is that the surface finish of a part may change its dimensions. A thick finish, like powder coating, may make the surface of the metal material thicker. Coatings can also change the surfaces and clearances of parts that must fit together. Finishes that use chemicals may eat away a small amount of the material and slightly change the dimensions. You need to figure out these things at the start of the project to make sure you get good results.

5) Price

Having thought about the things mentioned above, you should then think about how much money you have for the project. The best finishes often require a lot of time and effort to get right. They also need to use better materials. When it comes to manufacturing, all of these things add up to a lot of money. So, you need to think about these things and compare them to your budget before you choose a surface finish for your machine.

Final Thoughts

Some people think it’s a good idea to use CNC machined metal finishes on the finished parts they make. There are a lot of different ways to finish things, and each has its own benefits. This guide gives you enough information about the best CNC machining surface finish to help you make the right choice. It also talks about some things to think about before deciding on a surface finish.

People who work in manufacturing are always your best bet when it comes to deciding on a metal surface finish. Step Rapid is the best place to get help and advice from people who know a lot about things. The company’s experts know a lot about everything that goes into making things, including how to make things look good on the outside. We are ready to help you take your product to the next level, from product design to prototypes and large-scale manufacturing, and we can do it all for you.

People on our team can help you choose the best finish for a CNC machined part. When you finish your project, we make sure it’s strong, durable, and looks good. All you have to do is call us today, and we’ll talk about first-class rapid prototyping with you.