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Viking Drill and Tool St. Paul MN
America's Finest High-Speed Steel Cutting Tools™

Proudly Manufactured in the USA

NAS 907J Metric Cobalt Jobber Length

Type 643-D NAS 907J Metric Cobalt M42 Jobber 135° Split Point
Type 643-D Metric Cobalt Jobber 135° Split Point


Cobalt drill bits are not made of pure cobalt, but rather a steel alloy 8 percent cobalt.
— Use on tough metals, free machining stainless steel, titanium alloys
     and certain abrasive plastic.
— Cobalt drills require rigidly held positive feed drilling application.
Proudly manufactured in the USA.


Adobe Acrobat Logo PDF — Type 643-D Metric Cobalt Jobber Length

 


Drilling Speed
Cutting speed may be referred to as the rate that a point on a circumference of a drill will travel in 1 minute. It is expressed in surface feet per minute (SFPM). Cutting speed is one of the most important factors that determine the life of a drill. If the cutting speed is too slow, the drill might chip or break. A cutting speed that is too fast rapidly dulls the cutting lips.