Typically, when you need to drill a hole, you reach for a drill and bits. But when it comes to larger holes, you’re going to need something bigger, such as a hole saw.
Sometimes referred to as a hole cutter or holesaw, this special type of drill bit is an absolute necessity for creating medium-sized holes quickly. It attaches to your corded or cordless drill as any normal bit, and may be used to cut holes in ceramic, concrete, glass, metal, plaster, stone, or wood.
Unlike regular drill bits, the hole saw is a hollow cylinder wrapped around a drill bit with saw teeth along the edge. The depth of the cylinder limits how deep you can cut, although there are some ways to remedy this limitation.
They’re almost always made of steel and the cylindrical shape allows them to make very accurate holes quickly. Like drill bits, there are a large number of different hole saw sizes available although you’ll likely to only ever need to use a handful.
Hole saw kits are popular option since they include many of the most commonly used sizes and are almost always a better value than purchasing individual pieces.
Sinking Your Teeth In
There are three different types of teeth available on the hole saw, each with its own purpose.
Serrated teeth are the most common and resemble the teeth of a regular saw. These teeth are set at approximately 60 degrees and work best on plaster, plastic, soft metals, and wood.
Square teeth (or gulleted) are more heavy-duty than serrated teeth and are wide-spaced to provide more raw power. They’re best used on brick, ceramic tile, concrete, glass, or stone.
Have you ever watched in awe as Grandpa took out his false teeth and tore into a steak? That’s the same mysterious power of a coated hole saw. These toothless cutting edges are coated in an ultra-tough substance such as diamond or tungsten carbide, making them useful in industrial settings. Coated bits are used mainly for ceramic, concrete, and heavier metals.
Hole saws come in a wide assortment of sizes, both in length and diameter. The length is important, as it affects how deep the attachment can cut. These generally range from 7/8” (22mm) to 14” (350mm) deep.
An arbor extension can increase the potential cutting depth. Regardless of size, you may have to pause to chisel out the contents occasionally if you want to cut deeper than the length of the hole saw.
Common Hole Saw Sizes
The sheer number of available diameters available can get confusing visually. Thankfully, most will have the size stamped or written on the side for easy reference. You will usually only need a handful of these sizes to finish everyday projects.
Here are eight common sizes and what they’re typically used for:
- 9/16” (14mm) – Creating holes for domestic pipework and cable/phone lines
- 1″ (25mm) – Door latch
- 1-1/4” (32mm) – Holes for 1” pipes
- 2” (51mm) – Wire/cable holes in desks or entertainment centers
- 2-1/8″ (54mm) – Door knob or deadbolt (lock body)
- 3-1/2″ (89mm) – Ceiling electrical box
- 4-1/4″ (108mm) – Dryer vent
- 4-3/4” (121mm) – Drainage pipes or light fittings
Tip: For accurate SAE to Metric size conversions, click here.
Hole Saw Sizes Chart (w/ Recommended RPM)(RPM numbers are for typical bi-metal hole saws)
Recommended RPM (by Material)
|Inches||mm||Stainless Steel||Cast Iron||Mild Steel||Copper, Brass||Wood, Plastic, Aluminum|
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