End Mill Geometry/Training


Would you like to become an expert in the field of End Mill Geometries?

All end mills are not created equal and we want to teach you how to spot great quality from poor quality. We want you to understand why an end mill works great today, but not tomorrow.

Every day we build Tool Makers and Cutting Tool Engineers inside our plant, and now we are offering some of that same training to you.

Learn how to spot proper Micro End Mill geometry:

Good end mill geometry

Good end mill geometry


The picture to the right shows a view of a web & gash on a .040” two flute ball end mill. This is an example of what you want to see when viewing the top of a micro ball end mill. You can notice a white line running in almost an “s” pattern across the top of the end mill. This is your cutting edge. Next we will show what you don’t want to see… read more



Learn what end mill run-out is:

Runout - radial
Run out is differences or variations in the diameter of a cutting tool at certain points along the outside edge while the tool is rotating.

When an end mill is in rotation it is important that each tooth hits at the exact same spot along the work piece. If one tooth is hitting the work piece more than the others then that tooth is doing the bulk of the work. This will cause the end mill to wear and breakdown more quickly. Next let’s talk about axial run-out… read more


Learn how to spot a proper End Mill GASH & WEB Thickness:

Proper end mill gashFirst let’s go into a little bit of detail on exactly what we are referring to. During the manufacturing of an end mill there are various operations that create the necessary geometries which produce the final product. In this example we are teaching about Gash and Web Thickness. Without careful attention during the manufacturing process this is an area of the end mill that can easily be out of spec resulting in poor tool performance.

The Gash is the “operation of removing material” to create the Web Thickness along the very top of the tool. The Web thickness is the end result. Shown below on a 2FL End Mill (top view) it is the area in Yellow (gash) where it meets the thinnest point of the area in blue (web thickness result). Next we show views of a bad gash and what happens during poor manufacturing… read more


Learn how to spot a poor Corner Radius blend on a carbide End Mill:

Corner Rad EM - bad zoom1b
Carbide End Mills come in many shapes and sizes, in this article we are discussing a Corner Radius Carbide End Mill. There are several reasons why a corner radius end mill would be the tool of choice; but the most common would be for tool strength. A radius can prevent corners from chipping or breaking down.

It is critical to have a proper blend because any imperfection with the radius will be transferred directly to the part. This could result in many problems including poor finish, or leaving a line /ridge in the part itself. Reasons we don’t recommend adding a radius to a finished end mill… read more