The Difference Between 3D Printing and CNC Machining

Manufacturers must continually analyze and choose between production technologies with the increased demand for complex, engineered products and faster production lead times. When comparing methods for part production, it is beneficial to recognize the differences between 3D printing, also called Additive Manufacturing, and CNC Machining from a precision CNC machine shop. Each method has benefits, limitations and ideal part production specifications.

Advantages and Ideal Applications for 3D Printing

Learn More About the Difference Between 3D Printing and CNC Machining

Less Waste

3D printing is considered an additive process due to the method of adding layer upon layer to produce the finished product. CNC machining is a subtractive process where a machinist starts with a block of solid material, carving out the product shape. Depending on the size of the product and material used, 3D printing offers the advantage of less waste over the traditional precision CNC machine shop methods.

Easy Production Methods

Once the file is created and the material is set up, the 3D printer requires no operator to assist with the process. 3D printers range in price depending on materials used and the size required for the product.  While there is an advantage of not requiring technical, skilled labor to produce the parts, the product size is limited to the size of the printing bed.

Ideal Applications

3D printing is ideal in situations that require a quick prototype part, as a printer can typically print a part within 24 hours. This is not ideal in larger production runs, however, although it does meet the needs in quick prototype requirements. 

Complex geometry that cannot be accomplished with other methods are ideal for 3D printing, although this is largely dependent upon the material chosen. Most 3D printers do not have the ability to produce parts in the same materials available with CNC machines, limiting the applications to mostly polymers and thermoplastics. 3D printers that can print metal materials are new to market and cannot only be unreliable in meeting tight dimensions, but are also quite expensive. Therefore, 3D printers are ideal in prototyping applications where an available material is suitable in the application.

Advantages and Ideal Applications of CNC Machining

Multiple Part Runs

A precision CNC machine shop offers the advantage of quicker production on multiple parts, as a 3D printer must print one part at a time, one layer at a time. Additive manufacturing is typically not cost effective with multiple part runs. A CNC machining operation with skilled machinists and precision machinery can typically mass produce parts quicker than 3D printing. For large-volume production, another manufacturing method, such as injection molding, is ideal.


CNC machining offers the advantage of greater versatility with material selection as CNC machines can work on various metals such as steel, stainless steel, aluminum, copper, brass, tungsten and other materials such as Nylons, PVCs and various polymers.   


CNC machining is recognized for delivering high precision with repeatability, meeting tight tolerances up to +/-.001”. Due to the various material properties, thermal deformation can occur with 3D printing which can affect precision specifications depending on material and product design. CNC machining is still the go-to solution for producing parts with precision, durability with robust materials with heat and chemical resistance.

Precision CNC Machine Shop Ideal Applications

CNC machining is a tried and true traditional manufacturing method that only continues to improve and evolve with technology, still offering many benefits to companies with part production. Precision CNC machine shops deliver accuracy and precision with the ability to manufacture larger products than most printers and with more reliability to continually meet demanding specifications.

3D printing will not replace CNC machining due to limitations with materials and reliability meeting tight specifications, although can be an ideal alternative in less demanding applications. To learn more about the differences and which production method may be best for your process, contact the part production experts at QT Manufacturing. 

QT Manufacturing offers design and build solutions with prototype tooling, injection molded tools, injection molding and CNC machining of complex engineered parts. We are registered to ISO9001:2015 and AS9100 rev D, following a strict quality policy to meet the tight tolerances and deadlines required of critical applications. Contact us today for assistance in choosing the right technology for your part production.