3.9mm Black Finish HSS Jobber Drill

About this item:

• 3.9mm Black HSS Twist Drill
• Bordo Black Knight M2-HSS Twist Drills.
• DIN338
• 118° Split Point (crankshaft point)
• Split point is self centering and reduces the need for end thrust.
• Friction at workpiece is reduced.
• 118° point angles are ideal for use in materials such as mild steel and cast iron.
• The 118° point creates easily controlled chips which are wide and thin.
• Black Finish Twist Drills (also called blue finish) achieve their distinctive colour by steam tempering, a thermal process resulting in a porous tool coating.
• This surface helps to keep lubricant on the tool, particularly important on the cutting edges, thus reducing friction and cold welding. The result is increased tool life.
• Black finish tools are generally recommended for ferrous applications where the oxide layer aids chip flow and heat dissipation.