Endmills and drills sold in the UK are supplied with one of 3 coatings.

Endmills

TiAlN
These tools should be used on hard and high-toughness materials. Milling can be performed up to 60 HRC with high feed rates. It is recommended to machine with an air-blow or oil-mist coolant.

Hard Max
The latest coating supplied by Union Tool. It offers outstanding heat-resistant and lubricating ability with longer tool life. Recommended for hardened materials, especially over 60 HRC.

Cutting edge wear when machining a workpiece of 65 HRC, air cooled

It is broadly recongised that heat is a crucial factor in hard milling and the ability of the tool to retain its integrity under such extreme conditions is key. Based on this fact, trials to measure the new coating ability under extreme heat showed it remained hard up to almost 850°C, exceeding a similarly coated TiAlN tool by some 200°C.

Drills

Two coatings are used here:

• TiAlN on drills below 0.25 mm diameter
• TiCN on drills above 0.26 mm diameter