Understanding End Mill Substrates
In your world, the materials that you machine are constantly advancing and changing. In our world, substrates and coating are constantly advancing. We give you access to the best technology in the world, so that you can machine your parts easier and faster. We will help you hand pick the various combinations you’d like to test in your machining application.
Understanding End Mill Substrates
Cemented Carbide
The most popular substrate used in milling cutters/end mills, it is an alloy of Tungsten carbide (WC) mixed with cobalt (Co) to make a powder which is then pressed and sintered. The hardness of cemented carbide is at a level between diamond and sapphire and weight is about twice as iron. WC is the main ingredient and the cobalt functions as an adhesive.
Cemented carbide is hard but fragile, therefore it is important to consider the balance of hardness and toughness according to the intended use. The goal is to continuously improve upon corrosion, heat, and wear resistance. That is why Carbide Grades are available in an exceptionally vast range of combinations from a long list of elite manufacturers around the globe.
Components of Carbide Grades Include
Ingredients
Varying mixing ratios are used to create the ideal recipe. As well as adding additional ingredients, such as chromium, nickel, tantalum and titanium.
Cobalt (Co) Percentage
An increase in cobalt (Co) generally increases the transverse rupture strength and the toughness, but you will sacrifice some hardness. The percentage of cobalt is by weight. When someone says 10% or 12% Cobalt by weight, it actually equals a much greater amount by volume. A 12% cobalt content by weight could be more than 20% by volume.
Grain Size
Generally, as the Tungsten carbide (WC) particles become smaller, the material becomes harder. Smaller grain sizes also allow for a finer microstructure. It is critical to prevent grain growth during the sintering process.
Transverse Rupture Strength (TRS)
Or Flexural Strength, also known as modulus of rupture or bend strength. It’s a material property, defined as the stress in a material just before it yields in a flexure test.
Density
The density of a material is its mass / volume. Density is used to determine the general composition of the material
Each Cemented Carbide Grade Will Have Various Results for Each of the Following
- Strength vs % Co
- Hardness vs % Co
- Magnetic Saturation (Mag-SAT)
- Free Carbon (F.C.)
Because of the vast selection of cemented carbide grades available and the rapid pace of new advancements, we work with the carbide manufacturer directly to select the perfect grades for your machining goals.
Do you ever wonder if a different substrate would work better in your spindle? Call us today and let’s find out.
