It is simply a phrase that plays with words. The first saw is 'to see' in past tense. The second saw is the tool saw(noun). The third saw is 'to saw', the verb for using the tool saw. So to rephrase...
"Yes, a hole saw is a circular saw. It is primarlily used to cut through thin materials and is used in a drill. Hole saws, or circular saws, are used to cut wood, plastic, concrete, or stone,...
Today, automated tools are found in almost every area of manufacturing. Many companies that make mass produced cabinets and furniture etc. used computer aided tools to mill the wood and other...