Why use a titanium nitride coated gold series drill?
This is a commonly asked question, and the short answer is, they last longer. However, there is a longer story. The gold coating on the Alpha Gold Series drills is a Titanium Nitride (TiN) coating, that is applied using an advanced process called Physical Vapour Deposition (PVD) in a vacuum heat treatment plant. This process involves placing the ground and cleaned drills into a vacuum heat treatment chamber and creating a thin film coating using a low voltage electron beam with arc and magnatron sputtering. The coating is extremely hard –approximately 85 HRC (Rockwell C scale) compared to about 55-60 HRC for the hardness of a drill body and has a very low friction co-efficient.
Coatings can be applied in different thicknesses. Thin coatings are for rust resistance and appearance; thicker coatings are applied to industrial cutting tools such as jobber drills to significantly increase their life and durability.
The secret to cutting tool life in any jobber drill lies in the quality of the raw materials that are used, the hardness and tempering process used on the HSS material, and finally the design and grinding of the cutting edges.
Once the coating is worn off, the underlying qualities of the drills are unchanged, and tools can still be reground or resharpened to extend life. Drills supplied by leading brands such as the Alpha Gold Series drills use an industrial thickness coating which significantly increases the life of the drill.
Extensive independent testing has demonstrated that these drills provide over 30% more life and cutting durability than uncoated drills – making Alpha Gold Series Drills, Quality you can Trust!