What does it mean when the cutting edges on my core drill turn dark blue?
Question:
What does it mean when the cutting edges on my core drill turn dark blue?
Answer:
This primarily indicates an insufficient coolant supply.
Good cooling should always be ensured when core drilling.
Cooling should always take place via the lubrication device provided on the machine. This ensures internal cooling of the core drill cutting edges.
If the material is too hard and the wrong core drill is used, unwanted heat development can cause the core drill cutting edges to anneal.
It is essential to use carbide-tipped core drills for materials that are difficult to machine.