Machining Tips for PTFE/Teflon Parts You Need to Know Now

PTFE, or polytetrafluoroethylene, is a carbon and fluorine synthetic polymer. The commonly known brand name is Teflon by Dupont, it is a high-performance thermoplastic material. 

It has excellent properties such as low friction surface, high working temperatures, and chemical resistance, therefore, PTFE is widely used in various industries, like automotive, food processing, medical, and solar panel manufacturing, etc. 

However, it is challenge to CNC machining the PTFE parts to achieve tight tolerances, because of its unique properties, such as high thermal expansion coefficient and low thermal conductivity. 

In this article, we will discuss some tips to improve the machining quality of PTFE custom CNC machined parts.

CNC machining PTFE parts

1. Use the Right Machining Process.

PTFE can be machined using various processes, including CNC turning, CNC milling, CNC drilling, and CNC grinding. 

Depending on the application and the desired finish, choose the right CNC machining process that provides the best results. 

For example, CNC turning is suitable for producing cylindrical parts with tight tolerances, while CNC milling process is good for making the parts with complex shapes.

2. Use the Right Cutting Tool

The PTFE has low density and softness, so it is easy to be machined.

However, Teflon has low tensile strength and low thermal conductivity, to reduce the cutting forces and amount of heat generated during the cutting process, an extremely sharp and narrow cutting tool is recommended for CNC machining of PTFE parts.

3. Maintain the Cutting Tool.

To ensure consistent CNC machining quality, the cutting tool needs be checked regularly for wear and damage and replaced if necessary to maintain a sharp edge. 

4. Minimize Heat Generation.

PTFE has a low melting point, so the heat generated during the CNC machining process can cause the material to warp or deform, the worse case is to melt and stick to the cutting tool, resulting in poor surface finish and dimensional accuracy.

 To achieve fine surface finishes and tight tolerances , it is necessary to minimize heat generation by reducing the cutting speed and using coolants to reduce the temperature of the cutting tool and workpiece. 

5. Minimize the Vibrations.

Vibrations can cause the cutting tool to chatter, resulting in poor surface finish and dimensional accuracy. 

To minimize vibrations, use a rigid work-holding system to prevent the workpiece from moving or vibrating during the cutting process., Also, use a stable cutting strategy and avoid sudden changes in cutting forces.

6. Use the Proper Machining Parameters.

The CNC machining parameters, like spindle speed, feed rate, and depth of cut, are important for achieving good quality PTFE machined parts. 

Choosing appropriate parameters can prevent the material from melting and sticking to the cutting tool. However, the machining parameters should be adjusted according to the properties of the material, the geometry of the part,
and the desired surface finish.

7. Control the Chip Size.

PTFE produces long, stringy chips during the CNC machining process, which can wrap around the cutting tool and cause it to break. 

To prevent this, use a high-pressure coolant system to break the chips into smaller pieces or use a chip breaker to control the chip size.

8. Use Annealing Process.

The process of annealing can relieve the stresses in the material, to machine the PTFE part to tight tolerances, the PTFE stock should be annealed first, it allows it to conform more easily during machining. 

However, before making the final cut to the finished dimensions, it is important to anneal the PTFE part again to reduce or remove the stresses generated by the CNC machining process.


It is a challenge to CNC machine the PTFE parts of good quality, but by following these tips, you can achieve high-quality results and produce CNC machined parts that meet the desired specifications. 

Use the right machining process, use the right cutting tool and maintain it regularly, minimize heat generation and vibrations, use proper machining parameters, control the chip size, and use the annealing process.