When you stop to think about it, your cutting tools go through a lot. They are subjected to:
- High localised stress at the edge of the tool
- High temperatures along the rake face
- Sliding chips along the rake face
- Sliding of the tool along the newly machined workpiece
All of this without coolants and sometimes continuously for hours on end. All of this heat causes the immediate edge of the cutter to reach 550-750 degrees Celsius; in addition to the sheer amount of force placed on the cutter by the spindle and chip flow.
All of this heat is essentially melting away the cobalt (and titanium) light alloys which bond the wolfram particles of the carbide together within the rod. This begins to occur at temperatures as low as 300C.
So although the titanium carbide (Ti-C) that we use in our rods can withstand a lot of heat, if you let them cook for long enough they will start to get a bit rough around the edges.
This is where coatings benefit your tools:
- Lower friction
- Higher resistance to heat
- Higher resistance to impact
- Diffusion barrier between the tool and the chip
- The DLC (Diamond-like Carbon) coating used on our aluminium cutters can withstand 350-450C and the nano-tech coating used in our Xtreme Blue cutters can withstand up to 1200C.
Coatings also increase the hardness of the cutter substantially (up to 4200HV), absorb and disperse impact and reduce cutting friction. That being said,
they increase the thickness and radius of the cutting edge on your tools. Just as on a worn cutter, the once sharp edge will be rounded and dull. Putting a thick coating on a new sharp cutter essentially dulls the edge; resulting in a worse finish and more stress placed on the cutter.
Nano-tech coating’s innovative coating application technology allows its special titanium coating to be applied at a thickness of 0.0008-0.001mm; less than half the thickness of more common coatings, such as DLC (>0.002mm). Therefore, cutting tools with nano-tech coatings have all the longevity benefits of coating, with no reduction in the machined finish or increased stress on the cutter. In summary nano-coated cutters have:
- Increased resistance to heat and impact
- Increased hardness
- The same sharp edge as uncoated bits
This is what allows Xtreme Blue cutters to cut two times as many boards as regular uncoated cutters.