Forstner bits, spade bits and hole saws... oh my. When it comes to drilling relatively large holes, not all tools are created equal. Forstner bits, spade bits and hole saws each have unique capabilities, strengths and limitations. Understanding the differences can help you make the right choice for your project. Let's break it down:
What are Forstner bits, anyway?
Forstner bits are the go-to choice for creating a flat-bottom hole in wood. These are partial holes that do not break through to the other side. More of a specialty tool, Forstner bits are designed for precision and clean edges, making them ideal for woodworking projects that require an expert finish.
Best For: Creating large-diameter, flat-bottom holes for hinges and hardware
Advantages: Holes are clean and precise, and their walls have a smooth finish. The centering point, or spur, helps you stay oriented and avoid “walking” as you drill.
Limitations: Forstner bits do not produce a complete hole. More of a specialty tool, they're not necessarily for everyday use.
Size: Typically range from ¼" to 2 or 2 ¼"
Material Use: Wood
Common Applications: Woodworking, cabinetry, furniture making
And what exactly is a spade bit?
If speed and efficiency are the name of your game, turn to spade bits (also known as paddle bits). Sharp wings on either side of the centering tip work to tunnel through the wood as the bit spins. Spade bits are designed to quickly cut through soft material, namely wood, making them a practical choice for bulk drilling.
Best For: Quick and efficient holemaking in clean, nail-free wood
Advantages: Ideal for fast cutting and repetitive jobs, spade bits are cost-effective and often sold in multi-size packs. They’re also the better choice for drilling deep holes, when compared to hole saws and Forstner drill bits.
Limitations: These are not designed for metal, and nail-embedded wood will quickly destroy these bits. Spade bit holes are relatively rough, especially at the exit point, so they're not the choice if you need a clean finish. (Tip: To achieve a more aesthetically pleasing hole, try drilling from both sides to meet in the middle.)
Size: Spade bits have the smallest-diameter range among the three drilling tools, typically maxing out around 1 or 1 ½”
Material Use: Wood, plastic, formica
Common Applications: Creating holes for cables or pipes, or running wire through walls, furniture backs or other out-of-sight areas
Okay, so how about hole saws?
The heavy-duty solution for cutting large-diameter holes, hole saws consist of two parts: A circular saw blade is attached to a mandrel, which sticks out of the saw slightly and guides the saw blade into the wood. Instead of producing wood chips, hole saws leave behind a neat, disc-shaped puck.
When it comes to metal cutting, our Black Canyon carbide-tipped hole saws have teeth braised with carbide steel for extra hardness, strength and durability. In this case, the metal of your hole saw’s teeth must be stronger than the metal you’re drilling through—because whichever is softer is the one that will pull away.
Best For: Cutting large, complete holes
Advantages: With the widest variety of diameter size and the ability to handle both hard and soft materials, hole saws have the most versatility of the three.
Limitations: These cannot bore through very thick metal—not only will you run out of space to eject material, but your drill bit will overheat.
Size: Available in a wide range of sizes, up to 5” or more
Material Use: Wood, metal
Common Applications: Cutting sizeable holes in walls, ceilings and paneling without making a mess, or preparing a hole for a new lock
The Nitty Gritty on Bits
Forstner Bit | Spade Bit | Hole Saw | |
Holemaking Speed | Semi-Fast | Fastest | Semi-Fast |
Hole Size | ¼" ~ 2 ¼" | ¼" ~ 1 ½” | ¾" ~ 6” |
Clean/Rough | Clean | Rough | Clean |
Partial/Complete | Partial | Complete | Complete |
Material Capability | Wood | Wood, Plastic | Wood, Metal |
NorthSky Is Your Holemaking Hub
Professionals and DIY-ers alike know: Having the right drill bit for the task can be make-or-break. NorthSky’s comprehensive selection of holemaking tools—from Forstner bits to hole cutters, and everything in between—will help you tackle any project with confidence. Whether you’re crafting cabinets, running wires or installing a new light fixture, our precision drill bits deliver quality, durability and value, job after job.