Milling

Here at Cromwell, we stock a wide range of milling tools to suit every type of milling application. Made from high-quality materials, each tool profile is ground to exacting standards to deliver precision machining and just the finish you're looking for.

Browse our range of milling inserts from well-known suppliers, like Iscar®, Sandvik Coronmant® and Kennametal®.

What are milling tools?

Milling tools are used on automated CNC machines to fabricate a product from metal. Available in a wide range of types, these tools are designed for specific milling tasks to remove stock according to the requirements of a product design.

Why milling tools?

While milling tools must be chosen carefully for each task and set according to the parameters required by the CNC machine, once a job has been set up the automated process takes over and will consistently produce identical products.

When are milling tools used?

Milling tools are used in mass production applications where precision stock removal produces a consistent product time and again. Used for machining parts for a wide range of industries, milling tools ensure efficient and economic production.

Milling tool types

There are a variety of milling tool types on the market, each designed to maximise productivity. When selecting a milling tool, the operator has a lot to consider, including the milling type, pitch and geometry of a tool.

• End mills   -   These mills use the end and sides of the tool to cut laterally and axially

• Face mills   -   Mills horizontally remove stock from the surface or face of a workpiece

• Hollow mills   -   Mills a cylindrical shape

• Ball mills   -   Used to mill corners and for finishing

• Blade mills   -   Similar to end mills, these tools have blades to the side and on the face

• Thread mill   -   Mills a threaded hole for tapping

Considerations when choosing a milling tool

• Material - The characteristics of the material will highlight any issues a tool and operator will have to deal with, such as machinability, tolerances and chip forming capacity.

• Machine - The age and condition of the milling machine and its configurations can help to identify the correct tool for the job.

• Choice - Each milling tool type has its own features and benefits that can be an advantage or disadvantage to the application required.

• Cutting edges - the number of cutting edges will have an impact on the stability of the piece and the speed of progress.

• Geometry - Choose between the geometry of light, medium or heavy to suit the workpiece.

• Spindle - Go for the largest spindle size to ensure stability during milling.

• Chip formation - Choosing a tool with a larger cutting diameter than the cut required will help to reduce chip formation.

Milling tool jargon buster

We want to make it easy for you, so here are some key terms that will help you understand the range and applications a little better

• CNC - Computer Numeric Control milling machine

• DC - The diameter of the cutter (mm / inch)

• DCX - Maximum cutting diameter of the tool (mm / inch)

• Pc - The net power of the milling machine, which allows it to drive the tool (kW / Hp)

• Fz - The feed per cutting tooth

• n - The number of revolutions per minute a milling tool will make on the spindle (rpm)

• Vc- The cutting speed of the tool

• Mc - The torque or force produced by the milling tool when in use (Nm / lbf ft)

• Swarf - Also known as chips, this is the waste product created from stock removal

• Climb milling - A process by which a workpiece is fed to the milling tool to reduce force and pressure on the milling machine

• Feed - this is the speed that a workpiece is fed towards the milling tool. Feed rates are measured according to the insert used to ensure the correct cutting action

FAQs

What are milling chip types?

During milling applications, the stock removed from a workpiece is known as chips. There are different types of chips according to the workpiece material, the milling tool and the type of milling. These chips are named according to their shapes:

• Band chips - these are strips of material often produced during finishing programmes

• Nodal chips - these zigzag chips have a rough outer surface and smooth inner

• Chipped - small pieces of stock like garden chippings are produced when milling brittle metals

• Granular chips - when the stock removed cracks and separates into granules

What is a milling tooling system?

Known as MTMs (multitasking machines), a milling tooling system is a machine tool that will mill and turn during the same programme.