Precision machinery Graphite Mold Machining

1.High Precision Machining (cylinder tolerance ±0.02mm and hole tolerance ±0.015mm) 2.Great Roughness (Ra 0.477um)
HIT Graphite mold machining efficiency bar chart (Compared to Non-Ultrasonic)

HIT Graphite mold machining efficiency bar chart

 Work peice picture of HIT graphite mold machining

HIT Graphite mold machining picture

We can see quality performance from diffenent graphite mold parts. From observing hole, cylinder, and to surface roughness of whole work peice, it presents high precision and high stability (cylinder tolerance ±0.02mm and hole tolerance  ±0.015mm) without special purpose machine and tools.

The table below shows equipment we use and others commonly use in this case:
Milling Machine
Graphite Machine
Graphite Milling Tool
HIT Ultrasonic
3-Axis CNC+ 
HIT Ultrasonic Module
Plating Milling Tool

Highlights of HIT Ultrasonic Machining Module:
  • High Precision Machining (cylinder tolerance ±0.02mm and hole tolerance  ±0.015mm)
  • Great Roughness (Ra 0.477um)

HIT Highlights and compaison
CNC EDM HIT Ultrasonic+CNC
Special Purpose machine
& tools
EDM Equipment
(can see in tungsten carbide hi-efficiency case)
Normal CNC + End Mill
HIT Ultrasonic Machining Module
Difficulties and HIT Highlights
Excessive equipment and tools costs from purchasing specialized machine and hi-quality tools.
Easily scorched after EDM processing
With the assistance of
Intermittent ultrasonic high frequency vibrations , it can reduce excessive cutting force and subtly remove materials In every small vibrations, so that the it can both improve machining precision and stability.
Plug and Play module type can achieve the same and even better machining results in more flexible and economical way.


Graphite bears excellent mechanical properties such as high hardness, high hot - pressability, and well resistance to acid and alkali. It is often used as a mold in various industries, for example mechanical, electrical, and automotive industries.
The hard and brittle material properties makes difficult to cut, and the powder spraying during machining will invade then harm the equipment. To conquer challenges above, most of the graphite machining procedure will adopt special purpose machining.
In this case, we combined HIT Ultrasonic Machining Module with normal CNC machine and end mills to replace the use of special purpose machine. And we found that the machined results could not only meet client’s expected quality (surface roughness=0.477) but also significantly enhanced machining efficiency and quality stability. The efficiency improved to 200%, and at the same time  it could maintain the stability of the diameter at ± 0.02mm
Due to original mechanical properties and powder problems during machining, graphite usually requires special purpose machine and tools to process it. Which makes graphite manufacturers troubled with hi-cost equipment.
Besides, the brittle property is also prone to generate crack on the edge of artifact, and the crashing between tools and artifacts even shorten tool life, making cost problem form phasing out expensive specialized tools worsen.