Plastic Injection Molding


Centerless and Cylindrical Grinding

We specialize in the grinding of thermoplastic, thermosetting, composites, and in both end feed and through feed.

Centerless Grinding

Centerless Grinding is a machining process that removes material from the outside of a cylindrical item through the method of abrasive cutting in order to achieve the desired diameters, smoothness and roundness. 

The concept is relatively simple.  The workpiece is fed between two wheels rotating at different speeds.  The grinding wheel rotates at a speed that applies a downward force to the workpiece and grinds the workpiece while holding it in place. 

The regulating wheel (or moving wheel) applies lateral force to the workpiece and controls the rotational speed.  These wheels can have a variety of grain types and grit sizes, such as polycrystalline diamond or cubic boron nitride.  The different grit sizes on the wheel produce different diameters, widths, and thicknesses. 

The speed in which the two wheels move in relation to each other will determine how much material is removed from the workpiece. 

The most common types of centerless grinding are Through-Feed and Infeed. Through-Feed Centerless Grinding is used for parts with consistent roundness across their length.  The regulating wheel is positioned at an incline, which enables the wheel to rotate the workpiece against the grinding wheel while moving the along the grinding wheel laterally.  Infeed Grinding Centerless Grinding is the simpler of the two.  It is used for cylindrical parts with complex shapes or notches.  The workpiece rest blade is tooled to match the part’s shape.  The grinding and regulating wheels must also match the workpiece’s profile cut. 


  • Centerless Grinding allows a high-volume of parts to be processed at once because it occurs at a high-rate of speed.
  • This machining process can be used in a wide spectrum of fields, including aerospace, automotive, military, medical and more.
  • Though this is a fairly basic manufacturing process that has been used since the Industrial Revolution, there have been major technical updates in the centuries since.  CNC programmable controls can increase the efficiency of the grinding process by decreasing the time it takes to set up between jobs.  Robotics is also paving the way for automatic loading and unloading of workpieces.


Cylindrical Grinding 

Cylindrical grinding is a plastic forming process that uses a rotating wheel to grind plastics in to shape. Aztec Plastic specializes in cylindrical grinding of thermoplastic, thermosetting, and composite material.

Cylindrical or Infeed Grinding is a machining process in which a cylindrical object is clamped between two centers or a chuck, and then ground with a grinding wheel at a desired diameter. With cylindrical grinding, both the object and the grinding wheel are constantly rotating. This method of grinding does not leave a spiral or groove pattern, but it does create a smooth finish for plastic parts.


  • The ability to achieve extremely close tolerances and round angles with precision
  • A reduced cost compared to other plastic grinding processes.
  • Excellent finish quality on all cylindrical grinding projects.


  • ¼ to 4 inch diameter by 10 inch long sizes
  • Roundness
  • Hydraulic/Pneumatic areas of service

The Aztec Advantage 

Injection Molding

In 2014, we secured contracts with high-profile clients like Boeing, GE and Harley. 

Hear From Our Clients

“They [are known for] skilled, precision parts. They have a really specialized skill set…”

Please contact us if you have any questions about our services. 

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