Magnum™ Drills & Super Premium Cutting Tools
Welcome to the world of Magnum Super Premium twist
drills. This page will provide you with the opportunity to review the
many features and benefits of Magnum drills and to learn why they are
the finest tools available for most drilling applications. These heavy duty drills are recommended for use in tough metal drilling
applications and work hardening grades of stainless steel.
Magnum™ Vs. Cobalt
The Magnum™ drills will substantially outperform
cobalt drills in work hardening stainless steel applications. This
performance advantage is the result of construction differences between
the two types of drills. Cobalt drills, manufactured to Type J NAS
907 specs, have a very thick web. This web is necessary to limit
breakage of the brittle cobalt steel. Magnum drills are made of special
hi-moly tool steel, which is much tougher than cobalt steel. The web on
a Magnum drill can be thinned considerably due to the toughness of the
steel. (See Illustration A)
A Magnum drill with its thin web will penetrate
the work hardening stainless fast enough to continually cut beneath the
chip which is hardening from deformation. This means the drill is
cutting softer steel.
The cobalt drill, with its thick web, cannot be
fed at a fast enough rate to cut beneath the area which is hardening. As
a result the cobalt drill is continually drilling into hardened steel.
Stainless Steel: Work Hardening Vs. Free Machining
Work hardening grades of stainless are the 300
series with the exception of 303, which is free machining. Free
machining grades include the 400 series in addition to type 303. A quick
way to identify work hardening vs. free machining stainless is to
observe the chip formation. Work hardening chips break up during the
drilling process, while free machining chips are long and stringy.
Cobalt drills are recommended for free machining
stainless ( 400 series & 303), titanium alloys and other high
tensile strength materials. These applications require the high red
hardness of cobalt steel to counter the substantial heat generated in
the drilling process.
cutting tool may break or shatter under improper use. Government
regulations require use of safety glasses and other appropriate safety
equipment at all times in the vicinity of use.