Murakami Seiki's Scraping and Finishing process
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Scraping techniques make our ultra-precision machining possible

Scraping techniques make our ultra-precision machining possibleScraping ; Kisage is a man-crafted technique. It is to process ultra-precision machining and it enables an improvements in precision of a sliding surface and a surface plate of measuring equipments etc.

・Flatness is required to be smaller than 2 μm.
・Want to prevent precision lose from equipping large-sized machineries.
・Want to enhance the precision of your possessive equipments to improve technical skills.
・Do not have equipments for scraping.

Scraping enables to meet such demands and to provide high-precision machining. We have an AA-class technique, which is considered to be the finest skill for scraping. We are putting our efforts to inherit and provide high-class skills.

Benefits of Scraping

It is difficult to process and manufacture goods with fine precision if the precision of the machine tools, so-called mother-machine, is not developed enough.
When processing with machine tools, it may cause a dimension error which is said to be approximately 1μm, however it is possible to provide high-precision flatness, squareness and straightness with our skilled hand crafted scraping.

Benefits of Scraping

Kisage Technique ; Scraping

Examples of the Scraping Uses
Machine tools, Printing machines, Industrial machines and Special equipments etc.

Where to Scrape
Sliding surfaces such as table, column and head parts etc. of listed machines.

Concrete Works
We scrape the roughness off of the sliding surface of castings with a chisel shaped tool. Kisage technique enables to scrape 1 - 3μm off the surface at a time. With this technique, it is possible to form any shapes freely and yet precisely.


Purposes of scraping uses
Scraping applies to substantial parts where surface and object attach to each other. It enables to provide “stress-free” processes on the sliding surface.
Precision of the sliding surface is an essential element for machine accuracy. Because objects move on the sliding surface, it is required to be perfectly smooth. Otherwise the object may lose its balance as it moves. By scraping the sliding surface with Kisage technique, it makes microscopic oil sumps on the surface. These sumps provide the surface with protection and lubrication.

Purposes of scraping uses

Examples of Scraping Uses

Improving the precision of the surface - Lubrication and protection

Improving the precision of the surface - Lubrication and protection

The picture on left is the sliding surface finished straight and smooth with the machining processes. However, when the table moves on this surface, it may lose its balance on edges. With machine tools themselves, it is difficult to finish a whole surface with equal precision.

With Kisage technique, the hand-crafted scraping technique, we slightly lower the center part of the sliding surface (by a few μm which may differ depending on the size or machining methods of products) This enables the table to move on the surface straightly all the way to edges without losing its balance. It works for a vertical plane and a horizontal plane as well.

If Top Surface Requires a Fine Plane Degree

If Top Surface Requires a Fine Plane Degree

Scraping applies to parts where the surface and the object; such as head and column, head and spindle and, ball screw brackets and clamp face, rub against each other. It enables to carry out the “stress-free” processes.

In the case such as the example on the left, we can still connect surfaces together with the bolts. However this method may cause the upper surface curve. Therefore, we need to process scraping on the contact surfaces in order to make the surface flat and straight.

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Our Kisage-technique for scraping was elected as "Sakai Wazashu" brand

"Sakai Wazashu" is the official title for the Sakai city in Osaka, Japan's grant world-class companies or companies with excellent technical skills.

After its strict screening process, Murakami Seiki was appraised for providing high precision sliding surface with "Kisage technique" (=Scraping) which is impossible to process by machineries. The sliding surface is crucial for ultra-precision machine tools and measuring equipments.

Our Kisage-technique for scraping was elected as "Sakai Wazashu" brand

Technical Skills of Murakami Seiki ; Grinding methods which only fine craftsmanship can produce.


These are how we process Kisage as known as scraping.
However this only explains a small part of this technique.
No matter how much technology develops, Kisage technique is impossible to
mechanize and is always performed by a craftsman's hand.
In reality, the numbers of these craftsmans are decreasing.
Murakami seiki is also providing a technical consulting in order to
inherit our machining techniques.

If you are hoping to enhance your company's technical level,
willing to see the Kisage process, or want more information,
we would always be happy to help you with these requests and
to have you visit our factories.


Feel free to contact us about our ultra-precision assembly and machining

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