Bordo Fractional Left Hand Cobalt Tough HSS-Co5 Twist Drills.
135° Split Point (crankshaft point)
Split point is self centering and the short distance from the drill axis to the outer corners results in faster penetration, reducing the need for end thrust.
The 135° point should be used to cut harder steel materials especially in deep hole applications.
In these situations it will produce thicker chips minimising work hardening of the cavity.
Faster penetration reduces abrasion and friction along the cutting edges.
Cobalt HSS Twist drills are extremely hard and provide superior performance and increased tool life especially in stainless steel and high tensile steel.
Left Hand Twist drills are ideal for use with screw extractors to remove broken bolts and screws.
Bronze Finish (gold oxide) surface treatment. The metallic brown coloured low temperature temper treatment is normally only used on cobalt tools for identification purposes.
Sutton Tools Silver Bullet jobber drills are a general purpose drill bit designed for machine and hand held drilling in a wide range of ferrous & non-ferrous materials such as steel, aluminium, brass, wood & plastics.