Expert Quality, COB alt variable pitch hole saw manufactured from quality steel with 8% COB alt content for durability. Suitable for cutting steel, brass, bronze, cast iron, aluminium, wood and plastics. Maximum cutting depth 35mm. This Draper Expert Cobalt Hole Saw has a variable pitch for efficient cutting and is made from durable steel with 8% cobalt content. It can cut through various materials including steel, brass, bronze, cast iron, aluminium, wood, and plastics, with a maximum cutting depth of 35mm.