We design and develop hole cutting tools for the professional contractor which make hole cutting faster, easier, and safer. These same capabilities are valuable to the Do It Yourself homeowner undertaking a project with many holes or where the risk or cost of accidental damage is high.
People ask us what is the best hole cutter and in order to answer I need to know hole large the hole will be and the type of material being cut and how deep the hole needs to be. Each of these factors determines what hole cutter is going to work the best. For holes smaller than 5/8 inches in diameter in most materials a drill bit is going to work better than a hole cutter and the type of bit depends upon the type of material as different bits are needed for metal, masonry, tile and glass, wood, and plastics. With masonry and concrete drill bits are often the best tool for holes up to 1-1/2" in diameter.
The larger the hole the more torque is required from the drill and the more the efficiency of the hole cutter determines how big a hole can be made with a hand held drill, the drill power required, and the risk of backlash also increases. Choice of the best hole cutter for the hole size, depth, and material to be cut make a great difference in the drill power needed and the speed at which a hole can be bored. This in turn determines the minimum requirements of the electric drill that can be used.
It is surprising to most but the wrong choice of hole cutter can waste 90% of the power from the electric drill and take up to 10 times as long to bore each and every hole. Anyone with experience using high speed steel and cobalt drill bits has seen this difference in performance first hand. With holes from 3/4 inch up to 6 inches most people will usually use a bi-metal hole saw without a second thought and regardless of whether they are drilling in soft wood, hard wood, engineered woods (TJI, chipboard, oriented strand board, plywood), Hardie and other fiber cement board products, fiberglass, or plastics. This is a mistake.
Although bi-metal hole saws are the cheapest hole cutter available they are only well suited for drilling in mild steel that is 1/4" or less in thickness. For any other material they are a poor choice and often a much more expensive choice on a basis of holes drilled per dollar spent, not even considering the much longer time required to drill the holes and to remove the cut slug from the hole saw.
Big gullet hole cutters have multiple large teeth instead of the many tiny teeth of a hole saw. The teeth on these hole cutters extends past the inner and outer side walls of the hole cutter and this eliminates side wall friction as the hole cutter cuts. All the power of the drill goes into cutting instead of burning the workpiece. These big gullet hole cutters, like the Blue Boar TCT, will enable a drill to cut a hole 3 times as large and in 1/10th the time as with a bi-metal hole saw with the same drill. This makes it practical to use even a 18 volt cordless drill to bore holes 6 inches in diameter in materials over an inch thick.
Some of the big gullet hole saws, like the Milwaukee Tools' Big Hawg hole cutters use high speed steel teeth. These resist nail impact very well but dull quickly when used in engineered wood products, like MDF and particle board, and are not the best choice for abrasive materials such as fiber cement board, sheetrock, plaster, tile backer board, or fiberglass. For these harder materials the much harder tungsten carbide teeth will perform much better and stay sharp longer. With more than 5,000 different grades of tungsten carbide the manufacturer needs to match the grade to the materials that will be cut with the TCT hole cutter.
To summarize:
- Holes smaller than 3/4" in materials other than concrete use a drill bit (wood spade, HSS or cobalt, diamond)
- Holes smaller than 1-1/2" concrete use a carbide tipped masonry drill bit
- Holes 3/4" up to 8 inches diameter in sheet metal or thin mild steel plate use a bi-metal hole saw
- Holes 3/4" up to 8 inches diameter in stainless steel or thick metal plate use a TCT tungsten carbide hole cutter
- Deep Holes 3/4" up to 7 inches in diameter in wood, fiber cement board, fiberglass, sheetrock, plaster, MDF, chipboard, TJI, asbestos tile, non-fired clay tile, and stucco, use a TCT hole cutter with tungsten carbide teeth
- Holes to 1-1/8" deep and 1-7/8" to 17" diameter in wood, sheetrock, plaster, fiber cement board, fiberglass, MDF, chipboard, TJI, asbestos tile, plastics, rubber, acoustic ceiling tile, Formica, FRP, and similar materials use an adjustable hole cutter.
There are different quality and performance levels within these groups of hole cutters but the first step is to pick the right type for the job based on the material type and thickness and the hole size needed. The more holes you make the more time and money you will save by using the right type of hole cutter for the job. |
