When working with wood, having the right tools for the job is crucial for success. One of the most useful tools for cutting holes in wood is the hole saw. But with different sizes, tooth configurations, arbor types and more, it can be tricky to know which hole saw is the best choice for your woodworking project.
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What is a hole saw?
A hole saw, also known as a hole cutter, is a cylindrical saw blade that is used with an electric drill to cut holes in wood, metal, plastic and other materials. The hole saw attaches to a drill bit, which provides rotation. As the hole saw spins, its cutting teeth around the perimeter of the cylinder bore into the material to cut out a clean, circular hole.
Hole saws come in different diameters, typically ranging from 1/4 inch to 6 inches or more. They allow you to drill precise, uniform holes for things like doorknobs, handles, electrical boxes, plumbing, junction boxes, switches, outlets and more. The open cylinder in the center lets you pop out the “plug” of material in the middle after drilling.
Types of hole saws
There are several different types of hole saws to choose from when working with wood:
Bi-metal hole saws
Bi-metal hole saws have teeth made from high-speed steel and a body made from lower grade steel. The high-speed steel teeth stay sharp much longer than standard bi-metal or steel hole saws. Bi-metal hole saws work well on wood and other soft materials like laminates, melamine, plastics, drywall and some metals. They provide good value given their durability and low cost.
Carbide grit hole saws
Carbide grit hole saws have teeth embedded with very hard tungsten carbide. This allows them to cut faster, smoother and cleaner than other types, especially in hardwoods. Carbide grit hole saws last the longest of any type but are also the most expensive.
Diamond hole saws
Diamond hole saws have industrial grade diamond particles bonded to the teeth. This specialized construction allows them to cut through virtually any material quickly and smoothly, including steel, concrete, tile and masonry. Diamond hole saws work on wood but are best reserved for very hard materials where longevity and performance overrides cost.
Cobalt steel hole saws
Cobalt steel hole saws contain 8% cobalt alloyed with the steel. This mixture boosts strength and heat resistance. Cobalt steel hole saws stay sharp longer than standard bi-metal designs. They work well on most woods and can occasionally tackle metal when lubricated. Cobalt steel is a good choice when you need better longevity than bi-metal but don’t want the cost of carbide grit.
What size hole saw do you need?
Hole saws come in fractional inch diameters starting around 1/4-inch up to several inches. The most common sizes used for wood are:
- 1/4 inch
- 3/8 inch
- 1/2 inch
- 3/4 inch
- 1 inch
- 1-1/4 inch
- 1-1/2 inch
- 2 inch
- 2-1/2 inch
Matching the hole saw size to the application is important. For example, a 1/2-inch hole saw would be used to drill holes for thin cords, smaller electrical wires or plumbing lines. A 1-inch hole saw creates holes for larger electrical boxes and conduit. Know the required diameter before choosing the hole saw size.
Tooth configuration
The number, type and grinding of the teeth on a hole saw also contribute to cutting performance. Some key tooth configurations include:
Variable tooth
Variable tooth hole saws have staggered tooth patterns with alternate top angles ground into groups of teeth. This uneven configuration cuts aggressively while leaving clean edges on the hole. Variable tooth is a good general purpose design for wood.
Concentric tooth
Concentric tooth hole saws have the same tooth pattern repeated uniformly around the perimeter. This ensures smooth cutting and reduces vibration. Concentric patterns work well in thick wood and other materials where reduced vibration is helpful.
Raker tooth
Raker tooth hole saws have unique teeth aligned to score the material before the cutting teeth. This layout allows faster cutting with reduced chatter. Raker tooth designs are ideal for hardwoods but leave rougher edges on the hole.
Perma-tooth
Perma-tooth hole saws have triple rows of uniform teeth arranged in concentric steps. This configuration cuts aggressively and delivers excellent life in hardwoods. Perma-tooth is a good choice when longevity and fast cutting are essential.
Arbor type
The arbor is the stem that fits into your drill and attaches the hole saw. Arbors come in two main types:
Pinned arbor
A pinned arbor has a small bolt that holds the hole saw in place on the arbor. This allows you to quickly change hole saw sizes with one arbor. Pinned arbors sometimes slip, so they may not be ideal for heavy-duty use. But the convenience factor makes them popular for general purpose use.
Solid arbor
On a solid arbor, the hole saw is welded directly to the arbor. This creates a stronger, slip-free connection capable of handling higher torque. Solid arbors allow greater cutting pressure without the hole saw failing off. But you need a separate arbor for each size hole saw.
Factors to consider when choosing a hole saw for wood:
Type of wood
The hardness, density and thickness of the wood you’ll be drilling is an important factor. Softwoods like pine are less demanding on hole saws compared to hardwoods like oak, maple or exotic species. Thicker woods require hole saws to cut deeper and sustain prolonged contact compared to plywood or veneer. Match the hole saw to the wood’s characteristics.
Hole size
Larger diameter hole saws need more teeth and surface area to clear out material. Smaller sizes can get by with fewer, larger teeth. Consider the size of hole needed and choose a tooth configuration suited to that diameter.
Cost
Carbide grit and diamond hole saws provide the best performance, but cost significantly more than bi-metal and cobalt designs. Balance your budget against any demanding cuts in hardwoods that would require the longevity of premium hole saws.
Usage frequency
If you only make the occasional hole, a basic bi-metal hole saw should suffice. But if you regularly work in wood, a carbide or cobalt model is worth the investment. Frequent use will require greater durability and tooth life.
Cutting speed
Variable and raker tooth hole saws cut the fastest, while concentric teeth promote slower and smoother cutting. Assess the trade-off between speed and cut quality for your needs.
Arbor fit
Ensure the arbor type and size fits your drill. Cordless drills often require small, threaded pin arbors. Corded drills and drill presses can utilize larger arbors. Test fit before operation.
| Hole Saw Type | Best Uses |
|---|---|
| Bi-metal | General purpose for soft and hard woods |
| Carbide grit | Hardwoods where longevity is needed |
| Diamond | Abrasive materials like tile and masonry |
| Cobalt steel | Frequent use in mixed woods |
Tips for using hole saws in wood
Follow these tips to get clean, accurate holes when using hole saws in wood:
- Secure the workpiece to prevent movement as the hole saw spins
- Start drilling slowly to score the outline before applying more pressure
- Back the hole saw out regularly to clear chips and sawdust
- Lubricate the hole saw and wood with light oil or wax to reduce friction
- Let the hole saw do the work; don’t force the cut or overload it
- For blind holes, avoid penetrating too deeply to prevent blow-out on the backside
- Clamp a scrap wood block behind thin wood to prevent tear-out as the hole saw exits
Conclusion
With so many types and sizes of hole saws available, it can be difficult to determine the best ones for cutting holes in wood. But understanding your specific needs in terms of wood type, cut quality, cost and usage will point you towards the ideal hole saw for the job. Bi-metal hole saws provide the best value for general home use, while carbide grit and cobalt designs are worth the investment for frequent cutting in hardwoods. With the right hole saw selected and proper cutting techniques, you can make quick work of boring clean, accurate holes in all types of wood.