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Flat Multi-Drill Type MDF
Product data
  • Start of sales: December 2014
  • Website
Flat Multi-Drill Type MDF

What is a Flat Multi-Drill Type MDF?

Sumitomo Electric manufactures and sells a variety of drills for drilling holes in automotive, aircraft and electronic parts.

The Flat Multi-Drill Type MDF is suitable for a wide range of drilling applications, since it can handle slopes, cylindrical and other non-flat surfaces that cannot be drilled with ordinary pointed drills.

Moreover, the burrs produced during drilling at the periphery of a through hole on the other side are less than half the size of those from an ordinary drill. The Flat Multi-Drill Type MDF comes in drill diameters ranging from 0.3 to 20.0 mm, and the product line-up will be expanded in the future.

What are the advantages of Flat Multi-Drill Type MDF?

The point angle of the drill is set to 180 degrees to enable drilling into any kind of surface, such as slopes and cylindrical surfaces, as well as into flat surfaces. It also is highly efficient for counter boring* since the bottom of the drilled hole is flat. All these are made possible by an innovatively shaped central cutting edge, RS Thinning. This shape features an increased cutting edge thickness for improved rigidity and also has wide flutes for chip removal. Moreover, the finely finished flutes are suitable for drilling into stainless steel.

Counter Boring: Making the upper part of a hole flat for improved nut seating。
Interview with Engineer
Yuma Kawakami
Round Tools Development Group, Tool Designing Department
Sumitomo Electric Hardmetal Corp.
Yuma Kawakami

What were the difficulties in developing the Flat Multi-Drill Type MDF?

To drill a hole into non-flat metal, the cutting edge must be sharp enough to bite reliably into the drilled surface, yet also strong enough to withstand the load. However, an exceedingly sharp cutting edge might break the drill due to excess load on the drill, while making the cutting edge too strong might impair the sharpness and cause the drill to break before biting the workpiece. The original shape of the central cutting edge, RS Thinning, was created through repeated trial and error to make the tool stronger while keeping the cutting edge sharp and reducing the load. RS Thinning reduces drilling vibration and ensures a good balance between sharpness and strength, resulting in excellent performance of the Flat Multi-Drill Type MDF.

What features of this product do customers like?

For example, the Flat Multi-Drill is appreciated by our customers because the drill offers improved productivity and lowers tool cost. When drilling a deep hole into an irregularly shaped surface, it is generally necessary to make the surface flat in advance, which is usually done using a tool called an end mill. By contrast, the Flat Multi-Drill enables the operator to achieve a flat surface with a single drilling, thereby reducing the processing time. In addition, the Flat Multi-Drill has longer tool life than that of end mills.

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