End Milling Tool Basics Computer Integrated Manufacturing © 2013 Project Lead The Way, Inc.

Common Cutting Tool Materials Product Creation CIM Product Creation Common Cutting Tool Materials High Speed Steel (HSS) Cobalt Powered Metal (PM) Cobalt Solid Carbide Carbide-Tipped High Speed Steel – Provides wear resistance and cost less than cobalt or carbide Good for general purpose milling of both ferrous and non-ferrous materials Cobalt (M-42: 8% Cobalt) – Provide better wear resistance, higher hot hardness and toughness than HSS. Allowed to run 10% faster than HSS. Cost-effective in machining harder materials such as cast iron, heat treated steels, and titanium alloys Powered Metal (PM) Cobalt – Cost effective alternative to solid carbide, powered metal is tougher and less prone to breakage. Good for high-shock and high-stock application such as roughing Solid Carbide – Primarily used in finishing applications. Carbide can run much faster than HSS and Cobalt due to its extreme hardness. 2-3x faster than HSS. Resistance to high temperatures and wear resistant. More rigidity than HSS which allows for higher accuracy with smaller tolerances. Carbide is brittle and tends to chip rather than wear. Heavy feed rates are more suitable for HSS and Cobalt Carbide-Tipped – Offers similar advantages to Solid Carbide. More cost-effective than Solid Carbide especially for larger diameter tools Project Lead The Way, Inc. Copyright 2008

End Mill Types Square End Ball End Corner Radius / Bullnose Tapered Product Creation CIM Product Creation End Mill Types Square End Ball End Corner Radius / Bullnose Tapered Roughing End Mills Coarse Profile Fine Profile Square End – Used for general milling applications Ball End – Used for contour milling and pocketing applications. Used to produce a radius in the bottom of slots or pockets for added strength. Used to create compound curves for molds and dies where sharp corners must be avoided Corner Radius – Helps reduce chipping on the tip. Best used in mold applications, removing more material faster than ball end mills. Tapered – Results in faster and freer cutting due to more evenly formed chips over the length of the flute. Roughing End Mills – Not designed to last long – designed to “hog” off material and increase productivity by taking heavier cuts in a fixed amount of time without creating vibration Coarse Profile – most common type found for roughing end mills. Good for deep slotting and heavy side cuts Fine Profile Designed to increase tool life. Good for profiling when conditions do not exceed (depth of cut) x (width of cut) > Diameter squared (D2) Project Lead The Way, Inc. Copyright 2008

Other Mill Types Lollipop T-Slot Face Mill Slot Drill

Flute Types Two Flute Three Flute Four/Multiple Flute More Chip Space Product Creation CIM Product Creation Flute Types Two Flute Three Flute Four/Multiple Flute More Chip Space Two Flute Centercutting Three Flute Centercutting Four Flute Centercutting Six Flute Centercutting Eight Flute Centercutting Two Flute – Greatest amount of flute space allowing for more chip carrying capacity. Used primarily in slotting and pocketing of non-ferrous materials Three Flute – Wile this tool has the same flute space as two flutes, it has a larger cross sectional area providing for greater strength and the ability to pocket and slot both ferrous and non-ferrous materials Four/Multiple Flutes – Ideal for finish milling. The additional flutes allow faster feed rates, but due to the reduced flute space, chip removal may be a problem. Produces a much finer finish than 2 and 3 flute tools Harder Materials Project Lead The Way, Inc. Copyright 2008

End Cut Types Center Cutting Non Center Cutting One or more cutting edges at the tip Allows cutter to plunge, drill, or ramp Greater variety of applications Non Center Cutting Used for side cuts of contouring an exterior surface. Used where plunging is not necessary

Typical Surface Treatments Product Creation CIM Product Creation Typical Surface Treatments TiN (Titanium Nitride) TiCN (Titanium Carbonitride) TiAlN (Titanium Aluminum Nitride) ZrN (Zirconium Nitride) TiN – Provides extreme hardness and heat resistance. Allows for higher speeds and feeds. Requires an increase of 25% to 30% in machining speeds vs. HSS TiCN – Harder and more waer resistant than TiN under conditions of moderate cutting temperatures. Can provide the ability to run the job at higher spindle speeds (50% over TiN). Requires an increase of 35% to 50% in machining speeds vs. HSS TiAlN – Ideal for extremely high temperatures. Allows for increase in surface feet per min (SFM), extended tool life. Requires an increase of 75% to 100% in machining speeds vs. HSS ZrN – offers improved finish when used in aluminum, brass, copper and other non-ferrous materials. Prevents edge buildup Project Lead The Way, Inc. Copyright 2008

End Mill Selection Summary Shortest possible end mill for greatest rigidity Two or three flutes for slotting or heavy stock removal Multiple flutes for finishing and greater rigidity Largest diameter possible for added strength, rigidity and productivity Cobalt, PM and Carbide for tougher and harder materials, and for high production needs Apply coatings for higher feeds, speeds and tool life

Milling Formulas RPM = SFM x 3.82 / Tool Diameter Product Creation CIM Product Creation Milling Formulas RPM = SFM x 3.82 / Tool Diameter IPM = RPM x # of Flutes x Chip Load Chip Load = IPM / RPM x # of Flutes SFM = .262 x Tool Diameter x RPM Revolutions per Minute (RPM): Revolutions the cutter has in one minute Inches per Minute (IPM): Number of inches the cutter passes through the workpiece in one minute Chip Load: The amount that each flute cuts during a single revolution of a cutting tool Surface Feet per Minute (SFM): This is the cutting speed of the end mill in the United States. It is the number of feet per minute that a given point on the circumference of a cutter travels per minute Project Lead The Way, Inc. Copyright 2008