Home Industry How Surface Roughness Affects CNC Machining Parts?

How Surface Roughness Affects CNC Machining Parts?

by Alice

CNC machining is used to manufacture medical devices, assemblies, or components that medical treatment procedures require. CNC machining, thus, is full-blown, bloomed industry that employs a number of processes to yield the final product.

The plastic or metallic material is thus continuously removed by CNC machining as the procedure proceeds toward the final steps. This is also called Subtractive Manufacturing. During this continuous cutting of the material, the surface roughness CNC parts are the concept that also flourishes.

This blog post exclusively deals with surface roughness and its effects on CNC machining. Keep reading to learn the concept of surface roughness and its effects on the parts.

What Is Surface Roughness?

Surface roughness refers to the unevenness or tiny peaks that one can feel upon touching the finished product at the end of CNC machining. A layman would call it a finished surface, but on the contrary, the International unified standards call it “Surface Roughness.”

The lesser the value of surface roughness, the more the surface smoother.

In other words, one can clearly assume how this surface roughness can lessen the value of the finished product.

Different factors are responsible for surface roughness, such as the friction between the surface and the tool and the high-frequency vibrations in the machining process. As a result of these happenings, the surface roughness, in turn, affects the parts.

How does Surface Roughness affect CNC Parts?

Affecting the Wear Resistance

Surface roughness accelerates wear and tear. It dramatically reduces the wear resistance as the surface area of the two mating surfaces reduces because of the unevenness. As a result of reduced surface area, the pressure is not evenly distributed, hence increased.

So, the greater the pressure, the faster the wear resistance.

Affecting the fit Properties’ Stability

Fit properties are associated with the connection strength of the part. Maximum peaks n the surface or unevenness destabilize the fit properties. Weakened fits like clearance fit and interference fit can result in loosely connected surfaces.

Surface Roughness and Fatigue Strength

Unevenness on the surface of parts brings fatigue to the parts. This is called fatigue strength. Large wavy valleys contribute to surface roughness, and these are extremely sensitive to stress concentration.

The presence of large wavy valleys thus increases the surface roughness resulting in fatigue strength.

Corrosion Resistance

Another effect of surface roughness on parts is reduced corrosion resistance. The uneven surfaces are more prone to corrosion by the penetration of corrosive gases and liquids. As a result, the metal surfaces are easily corroded because of the presence of tiny valleys on the surfaces.

Sealing Performance

It is because of the surface roughness that the sealing efficiency is reduced. As the surface is uneven, it doesn’t provide a good contact ideal for sealing.

Measuring Accuracy

Surface roughness is also found to have reduced measurement accuracy of the parts.


Surface roughness is a severe issue in CNC machining that affects the parts differently. This blog post has enlisted the effects of surface roughness on parts in detail. The unevenness of the surface is responsible for problems like reduced contact surface, reduced corrosion resistance, and much more.

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