In this Cutting Tool Tips column, MEGA Tech proud to present the history of the world’s first carbide drill, developed by Sumitomo Electric Hardmetal Corp., just in time for the launch of their economical SMD Series Indexible Head Drills in MSL Type for Soft Steel and Stainless Steel.
In more than 80 years of the history of cemented carbide, the development and launch of cemented carbide drills was an epoch-making event, which enabled machining in the manufacturing industry to undergo a remarkable evolution. In the area of drilling, it had been believed difficult to use cemented carbide for strength reasons. In 1982, Yoshikatsu Mori, engineer at Sumitomo Electric Hardmetal Corp. daringly met this challenge.
Drills differ from other cutting tools in that they need to additionally have the function of evacuating chips produced during cutting from the bottom of the hole. This was the inhibiting factor in developing a cemented carbide drill. One essential requirement for drills in machining is that they do not break. If chips are not evacuated, the drills will break. To clear chips smoothly, the flutes must be wide. If wide flutes are provided, it will result in an accordingly reduced cross-sectional area, and the drill will decrease in strength. In summary, the point was how to enlarge the cross-section of the drill for improved strength and remove chips smoothly through the narrowed flutes. This was the most difficult challenge.
“We took note of the chips. Large chips become stuck in the flutes of the drills. However, short and thinly cut chips are smoothly ejected. Through repeated prototype development and evaluation processes, we discovered that by adopting an arc-shaped cutting edge, it was possible to produce short and thinly cut chips for smooth evacuation. This was the most significant breakthrough in developing cemented carbide drills,” recalls Mori.
In 1984, after a two-year development period, production and sale of the Multidrill commenced. The market enthusiastically welcomed the product. The Multidrill was selected successively by a number of customers, including major automakers and demand for it grew rapidly. Compared with the conventional high-speed steel drills, the Multidrill boosted machining efficiency 4- to 10-folds, enabling drastic productivity improvement in machining.
Nonetheless, a drill is a cutting tool that may in some cases fail to demonstrate its true performance depending on the machine with which it is used, the condition settings, and usage. As a solution to this matter, they promoted educational activities such as visits for users, the development and provision of a training framework and the holding of training seminar. These efforts spurred the widespread use of the Multidrill.
During use, the cutting edges of a drill wear and become ineffective in cutting. To use the drill again, the cutting edges need to be re-sharpened to return them to their original condition. Naturally, the quality of the re-sharpened cutting edges must be as good as those of a brand new drill. At the same time, customers demand that they provide the service at low cost and within a short delivery schedule. To meet these challenges, they built a new model of a re-sharpening network by establishing a partnership with grinding service companies across Japan. Additionally, they worked on the development of re-sharpening equipment and provided programs to machine manufacturers.
Since its launch to markets in Japan and abroad for about 35 years, the Multidrill has evolved in various ways and played a critical role in innovating the manufacturing site in terms of productivity improvement and cost reduction.
The Sumitomo Electric Group is taking various approaches to create new materials in the areas of metallic and inorganic materials and process innovation based on the Company’s proprietary ultra-high pressure and powder metallurgical technologies. There is no doubt that Sumitomo Electric’s Multidrill will continue to evolve in the future, help innovate production sites in every part of the world and play a role in paving the way for next-generation manufacturing.
The SMD Type SEC-MULTIDRILL is an indexable type drill with exchangeable drill head, which has a radial serration design, for high precision and strength.
An exchangeable drill head provides a new cutting edge, higher productivity and cost efficiency with easy tool management. Regrinding allowance of 1.5mm to 3mm make further tool cost reductions possible.
It is available in MTL Type for General Steel, MFS Type for Spot facing, MB Type for bridge, and the new MSL Type for Soft Steel and Stainless Steel.
The main features of this new MSL Type line up are
1. Excellent chip control & stable machining due to the new straight cutting edge and unique R thinning design.
2. Less adhesion and breakage, and long tool life due to NX coating which uses Sumitomo original Absotech technology.
Article by: Sumipol & MEGA Tech
Reference: https://www.sumipol.com/