Polishing service

Here is some basic knowledge about polishing technology and some applications for our service.

What is polishing?

Polishing is the process to remove irregularities on the surface by using slurry (small hard particles). It is often used in the final process of manufacturing because it enables us to adjust size and geometric tolerance in μm (micrometer) unit by selecting the applicable abrasives and processing method per work pieces.

Usually the target materials are electronic parts requiring high precision and mold metals and ceramics, glass and various crystal materials used in optical equipment, or resins and plastics, However, TDC can handle any kinds of materials.

What is the difference between polishing and grinding?

“Polishing” and “grinding” are similar in the point; they remove the surface of the product.
Therefore, both are sometimes used interchangeably, but in some cases, we are going back and forth between cutting, grinding, and polishing processes for one product to achieve the required shape and accuracy.

Grinding is an abrasive machining process that uses a grinding wheel as the cutting tool and removes saw marks and levels and cleans the specimen surface
On the other hand, polishing uses free abrasives called slurry and removes the artifacts of grinding but very little stock and because of that, there is less damage to the object (processing stress and creation of a processing alteration layer), and therefore, higher accuracy can be achieved…
We select the appropriate polishing / grinding method to meet the required accuracy and processing purpose.

various polishing methods

There are various polishing methods depending on customers’ needs.


Lapping is a machining process to use lapping machine. which two surfaces are rubbed together with an abrasive between them, by hand movement or using a machine .In double-sided wrapping, the product is sandwiched between two flat plates (surface plates) and single-sided wrapping is a processing method in which the product is placed on a surface plate and pressure is applied from above to rub the product against the abrasive containing abrasive .It is applicable for things where flatness is extremely important, such as lens manufacturing and molds, blades, because lapping can produce extremely flat surface precisely.


It is similar to lapping in that it uses lapping machines and abrasives. However, polishing differs in that it uses soft materials such as cotton and felt. In addition, it is often used in the final process (polishing, mirror finishing, etc.) that requires a delicate finish by selecting the type of surface plate (pad) and the type of abrasives.


Grindstone is a processing method in which the grindstone is fixed and moved while being applied to the product, or the product is applied to a rotating grindstone to polish the surface. Sharpening scissors or knives with a whetstone is also one of example of grinding. Generally, it is called “polishing”, but strictly speaking, it is called “grinding”.

barrel polishing

Barrel polishing is used is to polish the surface by putting products and polishing stones, and a polishing agent called compound, which has a cleaning and smoothing action, in a large container and vibrating or rotating it. The advantage is that you can polish a large number of products.

coated abrasive

Coated abrasive means polishing with sandpaper. It is one of the fixed abrasive grain processing methods, in which the abrasive is evenly distributed on the surface of cloth or paper. It is placed in a ring shape on a so-called polishing belt and rotated and polished while applying the product to this.


Electropolishing is a method of immersing a product in an electrolytic solution and applying a direct current to obtain a polishing effect. This method is used when it is difficult to handle with other polishing methods, but it also has the disadvantages of limited metals that can be handled and higher cost.

Polishing procedure

The polishing process is roughly divided into” rough polishing, “” medium polishing, “and” finishing“.

In rough polishing, we use coarse abrasives to remove large irregularities, and in medium polishing, the surface is smoothed with smaller abrasives than rough polishing. The process of rough polishing to medium polishing is in charge of the work of removing a large amount of polishing allowance and creating the shape we need.

In the finish, the surface evened by medium polishing is polished with finer abrasive grains so that it becomes mirror-surface. Make fine adjustments to the accuracy. In mirror finishing, the amount of removal as a polishing allowance is very small because it is carefully polished little by little, but it is an important process for achieving high accuracy.

TDC’s polishing technology

In TDC’s precision polishing and lapping, the workpiece and surface plate both rotate respectively. As it approaches the finish, the abrasive (slurry) is changed to smaller abrasive grains. We explain TDC’s polishing procedure with a picture.

We offer the world’s highest level of ultra-precision machining and ultra-precision lapping, such as surface roughness, parallelism, flatness, and dimensional accuracy.


Metals Stainless Steel / Superalloy / Copper / Titanium / Aluminum / Molybdenum / Tungsten/ Nickel / Tantalum etc.
Ceramics Al2O3 / ZrO2 / SiC / Si3N4 / SiO2, Also Coating and Plating are acceptable
Crystalline Material BK7/ Crystal/ PYREX/ Quartz / Si/ SiC /GaN/ Sapphire/LiTaO3/LiNbO3/
Resin Engineering Plastics / PEEK/ PMMA /PEFE

Processing Achievement


  Polishing Lapping with GC
Flatness 0.1 μm 1 um
Roughness(Ra) 1 nm Pear skin Finish/ Frost
Parallelism 1 um 2 um
Tolerance ±0.5 um ±1 um


Wafer chuck plate, precision table

We process positioning plates and plates that require precision, which are used in semiconductor manufacturing equipment and precision measuring machines. It is possible to finish the flatness, parallelism, and dimensional tolerance with high accuracy, and to create the desired surface roughness such as smooth surface and satin ground.

Various crystal wafers

We perform precision CMP and thin polishing of wafers made of various materials such as silicon, sapphire, SiC, and diamond. We support from 1 sheet to small lots for experimental research to mass production.


We manufacture shims that guarantee high accuracy such as ± 0.5 um and ± 1 um with thickness variations of 1 μm in the field where precise assembly is required, such as precision measuring machines, electronic devices, and medical devices,

Test piece

Processing of test pieces used for friction and wear tests and tensile tests is also compatible with various materials. We also accept quick delivery.


Surface plate

We perform precision machining of surface plates used as reference planes in assembly and inspection that require an absolute flatness. In addition to stone surface plates and ceramic surface plates, we offer thermal spraying surface plates.


It is used in the production of various products such as plastic working, press working, and injection molding, and we perform precision polishing of dies where precision is extremely important. we handle not only flat surfaces but also complex shapes and uneven lens shapes.



We also process spheres for high-precision bearings and measuring probes. Ultra-precision can be achieved even for spherical surfaces where sphericity and surface roughness are crucial.

Polishing Processing

Here is our manufacturing processing.
Feel free to send us the drawings for inquiry and we will support all processing.


Make the shape of a thing using a cutting tool such as cutting tools, drills, or end mills. We can change the shape quickly and greatly.


Use fixed abrasive grains (grinding stones) to shape the object. Enable us to efficiently create the required dimensions, shape, and roughness.


By slightly polishing the object using free abrasive grains (slurry), we can finish with the specified tolerance, surface roughness, and shape accuracy.


Using the world’s highest level evaluation equipment, measurement is performed by professional staff in a measurement room at 20 ± 2 ° C and in a clean environment.


Ultrasonic cleaning is performed so that there are no visual stains or deposits.

6.Quality Assurance

Specialized staff check each final product one by one and carry out thorough quality control. We will deliver the inspection data as an attachment.


TDC’s ultra precise lapping/polishing technology enables us to realize high precision manufacturing.

The ultra-precision polishing technology enables high-precision manufacturing in various elements.

  • We deal with wide range of materials such as metals, ceramics, crystal materials, and resins in the size of □ a few micron to □ 800 mm.
  • We realize ultra-precision polishing and ultra-precision lapping with surface roughness Ra1 nm and Rz4 nm for shapes such as flat surfaces, curved surfaces, and inner and outer diameters of cylinders.
  • For other processing elements such as “parallelism 100 nm”, “flatness 30 nm”, “dimensional accuracy ± 100 nm”, “angle ± 3 seconds”, and “sphericity 50 nm” while clearing advanced “surface roughness”. High precision is possible.
  • Our technology is used for cutting-edge technologies in various fields such as electronic components, semiconductors, optics, medical care, aviation, space, automobiles, and energy.

Regardless of the material and shape, we can handle precision processing by our polishing service.
Please feel free to contact us for more information.

Feel free to contact us for any inquires.