CNC Machining vs. Traditional Machining

The precision manufacturing industry relies heavily on computer-numerical control (CNC) machining, including operations that once used engineer-operated equipment like routers, shaping machines, vertical millers and center lathes.  Manufacturers of many types of industries choose CNC machining because it provides efficient, expedient and precise production capacity ideal for creating large quantities of items normally produced with a grinder, router, center lathe, or shaping machine.  

In manual lathing, there must be a skilled technician for every machine, while with CNC machining, one skilled person can operate several machines.  CNC machining can produce a broad range of metal components used across many industries use due to their accurate, consistent and complex cuts.  Some examples of these industries are:  aerospace, automotive, electronics, firearms, hospitality, manufacturing, metal work, military, production and transportation.  The first CNC machines were developed by US Air Force mechanics in the 1940s.  These early machines used punched-paper technology as a driver which has evolved into today’s digital software.  CNC machining grew popular due to its ability to produce detailed and precise results in large quantities by using computers.  

Computer Numerical Control is different from typical PCs because the software used to control the machine is specially customized and programmed with G-Code, which is specific to CNC, that allows precise control of speed, location, coordination and feed rate. One person can delegate the machine work that would be the equivalent of multiple operators on lathes, grinders, routers, mills and shapers which human operators and conventional machines don’t always do efficiently.  The manufacturing field finds CNC machining very useful because this industry needs large amounts of metal and plastic parts, often in complex shapes.  Different types of CNC machines have the advantage of multiple axes that can adjust to difficult angles and help manage hard to cut materials. 

Basic machines have a cutting implement along x and y axes that each work independently and simultaneously.  Advanced machines may have up to five axes that perform similarly and have the capacity to turn and flip the part.  CNC machines can automate the jobs that require several cuts.  A router or spindle turns the cutting implement, which resembles a drill bit, and cuts the material, while a true drill bit only cuts at the tip.  The programming in CNC machines incorporates all the exacting, high-speed movements needed to produce the object and enables detailed customization.  CNC machining is becoming increasingly popular to fabricate metal parts and plastic parts, since it allows the manufacturer to produce complex shapes that would be close to impossible to create manually.  Many industries look to CNC machining advantages for production solutions involving metal and plastic and any number of machining processes they may need.  

CNC and conventional machines both start with a raw chunk of metal or plastic and shape it into a part.  The main difference between the two machines is the automation of CNC versus the manual nature of conventional.  Speed, production rate and accuracy are some of the main advantages CNC machining has over conventional machining.  A skilled employee programs software to cut the parts in CNC machining while with conventional the employee sets up and operates the machine and gears.  Conventional costs less and is usually used for small-quantity projects.  CNC is used for high quantities and is not as cost-effective for smaller projects. A CNC machine uses three tools to cut parts, while conventional machines require five tools and more time to get the job done. Conventional and CNC technologies are available for most machining jobs. Some of these include drills – a bit spins to make contact with the material, lathes – the block of material moves against the drill bit, usually in lateral motion and milling machines – rotary-cutting tools remove material from a stock unit. Novel CNC machining technologies include less common types such as electrical/chemical where the material block is cut using a specific kind of machining style such as electron beams, electrochemical, electrical discharge, photochemical and ultrasonic. Less commonly found methods of CNC machining involve cutting media like lasers, oxy fuel, plasma and water jets.

The use of computer-aided design (CAD) software is used in CNC machining to produce a two or three-dimensional model of the final component. The prototype image of that component is fed into the software which operates through the computer to direct the machining tools to produce items identical to the model. Once the computer loaded a new image for CNC machining, it is able to pull up that model numerous times to produce more of the item. This is designed to achieve machining accuracy within .0001.

Conventional and unconventional methods of CNC machining are employed for a plethora of jobs that may involve a variety of materials such as:


These are 20 cutting chores frequently completed by CNC machining:


Advantages of CNC Machining

Precision Components: The digital template and autonomous machining of CNC practically eliminates human error and achieve accuracy within 1/1000th.

Reliable Endurance: CNC machines work around the clock every day and only top for repair or maintenance.

High Production and Scalability: Once the design parameters and specification have been entered into a CNC machine, it consistently executes huge quantities and afford flexible scalability.

More Capability: When used in tandem with advanced design software, CNC machines create outputs that cannot be replicated by manual machines. Even the most gifted engineers can’t use conventional machines up to the level of CNC machines because of the advanced software that they use. These machines can produce any size, shape or texture needed.

Less Labor: CNC machining requires fewer personnel to execute the production tasks. One skilled operator can run several of the autonomous CNC machines while another programmer can get them loaded with the designs. A manual machines requires at least one skilled operator per machine and a supervisor. What you can save on manpower can be passed along to customers.

Uniform Product: When you use CNC machines over conventional machines, your CNC outputs match exactly. Even the most talented machine operations running traditional machines, their products will very slightly. Perfect parts are guaranteed every time with CNC machines.

Lower Costs: CNC machines have high speeds, are more efficient, precise and require fewer labor hours. Saving money or making more money is one of the popular benefits of CNC machining.

Fewer Headaches: Manual machines serve many great purposes but when your operator is out, or your staff isn’t performing up to their expectations you won’t produce as much as you would by using a CNC machine.

Better Safety: Even though CNC machines still require the use of operators, they are at a distance from the sharp tools. Operators of conventional-manual lathes, drills and punches come into direct contact with the implement.

Design Retention: Once the design has been loaded into the CNC machine software and it creates a perfect prototype, the program can easily retrieve the design and create the object over again.

Low Maintenance: The G-code based software will automatically update when needed and CNC machines usually do not require much service other than to change the cutting implements at the proper interval. None of the regular maintenance requires professional service.

Versatility: CNC machining creates virtually any component. Some of the models include special features and accessories that further expedite and simplify the production process.

There are many advantages to using CNC machines and at Sheldon Precision we only use the best machines to make sure your product is made with the highest quality possible. Contact us today for a quote at

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