High-speed variable pitch bi-metal hole saw ideal for cutting perfectly round and accurate holes in metals, plastics and wood up to a depth of 35mm (1.3/8”). It offers a hardened M3 steel cutting edge that is welded to a tough alloy steel body, making them very durable and hardwearing. The construction reduces the risk of shattering. The hole saw has four side slots for removal of slug, as well as a female threaded spindle for fixing to a 9.5mm arbor. It can be easily attached to power drills for a fast, clean, heavy-duty cutting action in stubborn materials. When metal cutting it is advisable to use a lubricant to prolong the service life of the hole saw, such as Stock No. 76109 - Metal Cutting Lubricant (400ml).