Choose the Right Finishes for Your CNC Machining Services

What is CNC machining? The full form of CNC is Computer Numerical Control, and it manufactures metal machine parts with the help of code controls assigned to it related to cutting heads, spindle speed, RPMs, etc.

While getting the CNC machined parts, we keep many factors in mind, like, its shape, dimensions, tolerance, quality of raw materials, and many more. But there’s one thing that most of us neglect – it’s finishing. The finishing is done after the production of CNC machinery, and it also needs to be taken care of and not just selected randomly.

Here in this article, I will brief you on how to choose the right finishing for your machine and different types of finishing. You can always ask the CNC services providing company for the quote as per the finishes.

Without much delay, let’s dive into the topic:

Factors to keep in mind while choosing the right finishing for the machinery:

 

1. Measuring the surface finish is essential, as you need to know what you are working on or with. There are different ways to measure the profiling area and microscopy for roughness and peaks.
2. Sticking to the right feeds and speeds will help you out in increasing the speed and reducing the feed, which will prolong the life of machinery.
3. No matter what tool you are using, make sure it doesn’t deflect or chatter, as it can give the CNC machine part a chippy surface finish.
4. Go for the balanced tooling technique to reduce the vibration.
5. For a better finish, look for the sharper inserts, lead angle, and a positive rake.
6. Minimize the runouts as it can eventually affect the surface finishing and functioning of the tool.
7. Avoid using the same tools for roughing and finishing, as it won’t only cut costs but also alter the quality of the finishing.
8. When the finishing process is going on, make sure there aren’t any dwells or pauses as they will hinder the uniformity of the finishing.
9. You must always use chip breakers as they can control the chips from making contact with the work-piece. You can’t just ignore the chip as it is one of the most important parts for getting a good surface finish.

Types of CNC Machine Finishes:

As said, you must always look for professional CNC services for getting the perfect surface finish regardless of its type, whether you are ordering a mold, end-use component, or the prototype. Here are few basic types of surface finish that every CNC machining company provides: You can also check CNC Machining China Services Precision Machined Parts.

As-Milled Finish

As-milled is one of the standard finish types of most companies. The as-milled finish keeps the surface of the substance as it is machined. It gives a dull and rough finishing. You will still see the tool marks on the surface, though you can always give additional polishing and smoothing to get rid of the machine texture.

The average roughness of the finished surface will be around 3.2 μm. So, if you think the roughness is more than you can accept, go for the additional smoothing process. It is one of the most cost-effective finishes in the CNC machining world. Also, it is the best type of surface finish for prototypes, jigs, and fixtures.

Bead Blast Finish

Bead blast finish works just like its name. Yes! The small glass beads are blasted against the designated surface to give the finishing. The bead blasting machine consists of small spherical glass beads that are blown towards the CNC machined part with the help of compressed air.

The bead blasting provides a smooth and uniform texture with either a matte finish or satin. The bead blast finish might alter the dimensions (slightly) and are suitable for aesthetic machines or tools that need spectacular visuals.

Powder Coat Finish

The powder coat finish reflects the method of spraying polymer powder to the machine surface, which will provide more strength and make it wear resistance. This type of surface finish works well on all types of machines be it small or large, mold or prototype.

If a single finish doesn’t satisfy or meet up with the desired machine look, you can always go for the second, third, and as many coats you want. However, keep in mind it will affect the dimensional tolerances.

Anodizing Type II Finish

Anodizing Type II coating provides a uniform and corrosion-resistant layer on the surface. With this type of finishing, you can even color the surface, and it also provides extended durability. Anodizing is mostly done on the metal machine parts.

One more thing you need to know before you finalize the surface finish type. The process of electrochemical coating is non-conductive, so make sure you cover the parts where conductivity is required. Also, this was type II anodizing, and there’s one more.

Anodizing Type III Finish

Last but not least is type III anodizing finish. What’s so different in that? Type III anodizing is for the machine types that need wear-resistance along with corrosion-resistant properties. It adds the specified thick layering on the substance and makes it durable for a longer period.

Just like type II anodizing, the coating in type III is also non-conductive. The anodizing can work for metals like aluminum, titanium, and magnesium. Type III anodizing is done on the engineering parts as well as aesthetic products.

The Bottom Line:

Believe it or not, the surface finish changes the look of the CNC machine as well as provides many benefits. Here in this blog, I tried to explain everything about the surface finishes and how you can choose the right one. As for cost, it will vary with the types.

Still to give you an overview, if you want to have finished just for protectiveness purpose, the as-milled is the best one. However, if the purpose is just decorative then, bead blasting or the powder coat is ideal. Anodizing is one of the perfect finish types to increase durability along with its looks.