M42 Cobalt Shell End Mill
NIAGARA M42 Cobalt Shell End Mill - Tool Material: M42 Cobalt   Number of Teeth: 14   Series: RD   Tooth Pattern: • Right hand helical tooth and roughing tooth designs.   SIZE : 4   HOLE DIAMETER : 1-1/2

M42 Cobalt Shell End Mill

Made In The USA
Item #: 10-909-994
Size: 4"
Length of Cut: 2-1/4"
Hole Diameter: 1-1/2"


  • For milling operations where a larger diameter end milling cutter is preferred.
  • Designed as arbor mounted cutters for machine tools.
  • Slots cut into back end of shell body are used to engage driving lugs on the arbor, providing a positive drive and preventing any possibility of slippage during use.
  • For heavy duty and rough milling applications.
  • Well suited for either ferrous or non-ferrous materials where they offer high wear resistance for both general purpose machining and "exotic" metals.


  • Sized and proportioned to afford a good cutting range and ample rigidity.
  • Right hand helix, ground flutes, high rake geometry and a high resistance to cutting temperatures and cutter wear.
NIAGARA RD Series M42 Cobalt Right Hand Heavy Duty Shell End Mills
Product Specifications
Size 4"
Length of Cut 2-1/4"
Hole Diameter 1-1/2"
Tool Material M42 8% Cobalt
No. of Teeth 14
Cutting Direction Right Hand
Model # N09994
Operation Heavy duty
Prop. 65 Yes
Series RD
Tooth Pattern Right hand helical tooth and roughing tooth designs.
Type M42 Cobalt Shell End Mill
Weight 4.875 lbs.
Prop 65 Warning Many metalworking products do contain metals that are included in the latest Prop 65 warning. Exposure to the elements can be harmful. May cause cancer and reproductive harm.