Troubleshooting
Cutting-Edge Chipping: Causes and Fixes
A chipping edge looks like wear but isn't — it's overload or vibration. Here's how to tell the difference and protect the edge with the right prep and corner radius.
Chipping is mechanical, not thermal — tiny fractures along the edge from shock, vibration, or an edge that's simply too sharp for the material. It often gets misdiagnosed as wear, but the fixes are different: where wear wants less speed and more coolant, chipping wants more rigidity and a tougher edge. Here's how to tell which you have and stop it.
Edge chipping — causes & fixes
Strengthen the edge with T-Process
A perfectly sharp edge has nothing behind it — in steel and stainless that knife edge fractures under the shock of each tooth's entry. RobbJack's T-Process is a controlled edge preparation that adds microscopic strength to the cutting edge, dramatically improving chip resistance in ferrous materials without turning the tool into a rubbing, heat-generating burr.
Protect the corner
The corner is the most fragile point on a square end mill — it's where two edges meet at a sharp point and where chipping starts. A corner radius converts that vulnerable point into a strong arc, spreading load and resisting the fracture that propagates back into the flute. If you don't need a dead-sharp corner on the part, run a radius.
Kill the vibration source
Chronic chipping with no obvious parameter cause is usually chatter or a loose setup transmitting shock to the edge. Tighten the fixture, shorten the tool, and check runout — see the Chatter guide. When the grade or geometry is simply wrong for the material, RobbJack's application engineers will spec the right substrate and edge.
Chipping is overload and vibration, not heat — stiffen the setup, strengthen the edge with T-Process, and radius the corner.
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