types of milling tools

Milling is one of the most versatile machining processes, capable of performing operations such as cutting, drilling, shaping, and contouring. The effectiveness of milling depends heavily on the type of cutting tool used. This guide explores the various types of milling tools, their applications, materials, and best-use scenarios.

1. End Mills

End mills are the most common milling cutters, used for profile milling, slotting, and plunging. They have cutting edges on the ends and sides, allowing for both axial and radial cuts.

Types of End Mills:

Flat End Mill – Produces flat-bottomed grooves and slots.

Ball Nose End Mill – Rounded tip for 3D contouring and mold making.

Corner Radius End Mill – Slightly rounded edges to reduce chipping.

Roughing End Mill (Ripper) – Designed for rapid material removal with serrated edges.

Tapered End Mill – Used for die sinking and angled walls.

Materials:

High-Speed Steel (HSS) – General-purpose, economical.

Carbide – Harder, more wear-resistant, suitable for high-speed machining.

Cobalt Steel – Heat-resistant, used for tough materials like stainless steel.

Applications:

Aerospace components

Mold & die making

Automotive parts

2. Face Mills

Face mills are used for facing operations, creating flat surfaces on a workpiece. They consist of multiple replaceable indexable inserts mounted on a solid body.

Types of Face Mills:

Square Shoulder Face Mill – Produces sharp 90° corners.

High-Feed Face Mill – Designed for rapid material removal.

Copy Face Mill – Used for roughing complex shapes.

Insert Materials:

Carbide – Most common for general machining.

Ceramic – High-speed machining of hardened steels.

CBN (Cubic Boron Nitride) – For superalloys and cast iron.

Applications:

Large surface finishing

Heavy-duty milling

3. Slab Mills

Slab mills are wide, heavy-duty cutters used for large surface milling. They have straight or helical teeth and are typically mounted on horizontal milling machines.

Applications:

Machining flat surfaces on large workpieces

Heavy industrial milling

4. Side-and-Face Cutters

These tools have cutting teeth on the periphery and sides, making them ideal for slotting and grooving.

Types:

Staggered Tooth Cutter – Reduces vibration in deep cuts.

Interlocking Side Mills – Used for wide slots.

Applications:

Keyway cutting

Spline milling

5. Fly Cutters

Fly cutters consist of a single-point cutting tool mounted on a rotating body. They are used for fine finishing and large surface machining.

Advantages:

Low-cost alternative to face mills

Excellent surface finish

Disadvantages:

Slower than multi-tooth cutters

Applications:

Surface finishing on aluminum and plastics

6. Hollow Mills

Hollow mills are tube-shaped cutters used for turning-like operations on milling machines. They produce smooth cylindrical surfaces.

Applications:

Precision shaft finishing

7. Thread Mills

Thread mills are used for cutting internal and external threads. Unlike taps, they can produce threads in hard materials and blind holes.

Types:

Single-Form Thread Mill – For small production runs.

Multi-Form Thread Mill – Faster for high-volume threading.

Applications:

Aerospace fasteners

Medical implants

8. T-Slot Cutters

These specialized tools are designed to mill T-slots for clamping workpieces.

Types:

Standard T-Slot Cutter – For general use.

Undercutting T-Slot Cutter – For deeper slots.

Applications:

Machine tool tables

Fixture clamping systems

9. Dovetail Cutters

Dovetail cutters create angled grooves for sliding joints, commonly used in machine tool slides.

Types:

Single-Angle Dovetail Cutter – For standard dovetails.

Double-Angle Dovetail Cutter – For symmetrical grooves.

Applications:

Tool holders

Industrial jigs

10. Woodruff Keyseat Cutters

These are small-diameter cutters used for milling keyways in shafts.

Applications:

Gear and pulley keyways

11. Involute Gear Cutters

Specialized cutters for milling gear teeth with precise involute profiles.

Types:

Gear Hobs – For high-production gear cutting.

Form Relieved Cutters – For custom gear profiles.

Applications:

Automotive transmissions

Industrial gearboxes

12. Reamers (Milling Reamers)

Used for finishing pre-drilled holes to tight tolerances.

Types:

Chucking Reamer – For general use.

Adjustable Reamer – For varying hole sizes.

Applications:

Precision bore finishing

13. Chamfer Mills

Chamfer mills create angled edges (bevels) on workpieces for deburring or aesthetic purposes.

Types:

Single-Angle Chamfer Mill – For standard chamfers.

Countersink Chamfer Mill – For screw head seating.

Applications:

Edge finishing

Weld preparation

14. Corner Rounding End Mills

These tools round off sharp edges for safety and aesthetics.

Applications:

Decorative metalwork

Consumer product edges

15. Drill Mills (Combination Tools)

Hybrid tools that can drill and mill, reducing tool changes.

Applications:

Light machining

Prototyping

16. High-Performance Milling (HPM) Tools

Designed for high-speed machining (HSM) and hard milling, these tools use advanced coatings like:

TiAlN (Titanium Aluminum Nitride) – Heat-resistant.

Diamond Coatings – For non-ferrous materials.

Applications:

Aerospace alloys

Hardened steel dies

Conclusion

Choosing the right milling tool depends on factors like material, operation type, precision requirements, and machine compatibility. Carbide tools dominate high-speed applications, while HSS remains cost-effective for general machining.

For roughing, use ripper end mills or high-feed face mills. For finishing, ball nose and fine-pitch end mills are ideal. Thread mills and T-slot cutters serve specialized purposes, while HPM tools push the limits of modern machining.

Would you like recommendations for specific materials or milling strategies?