Metal drill bit vs wood: Which is right for your project?

Choosing the right drill bit for specific DIY and assembly projects can be difficult with so many types of drill bits available out there. The decision process can be a little overwhelming, especially if you are a beginner. 

To help you out, here’s a metal drill bit vs wood guide to understand the key differences between these popular drill bits. This way, you can avoid selecting the wrong drill bit, ensuring you experience a smooth and efficient drilling process. 

What is a metal drill bit?

A metal drill bit is a versatile cutting tool for drilling holes into metal surfaces. It’s ideal for fabricating metal parts, installing metal fixtures, assembling furniture, home repairs, and various DIY projects.

It comes in many types, but the most common one is the twist drill bit. This type is made from high-speed steel (HSS), a tool steel composed of carbon, iron, and various metals. One advantage of using an HSS drill bit is that it can maintain its hardness for long periods and has high heat resistance. Cobalt and carbide steel are other popular materials for metal drill bits used for stainless steel, cast iron, and other rigid materials.

What is a wood drill bit?

A wood drill bit has a similar cutting function, but it’s designed for drilling holes in various wooden surfaces, such as oak, walnut, composite wood, and a whole lot more. 

Like a metal drill bit, a wood drill bit comes in many types, each with unique applications. Brad point drill bits are ideal for furniture making, spade bits for plumbing and electrical wiring, forstner bits for hardware installations, and auger bits for woodworking and construction projects. 

Although there are many variations of wood drills, these cutting tools share some standard features. They all have pointed protruding edges or spurs to prevent the bit from wandering, maintaining precision while drilling. You’ll also notice that wood drill bits have grooves that help remove wood shavings, keeping the wooden surface clean after drilling. Moreover, they usually have sharp cutting edges to avoid splintering or tearing the wood while drilling. 

Wood drill bit vs metal: Which drill bit should you use for assembly projects?

Here, we’ll further break down the distinct features of a wood drill bit and a metal drill bit to help you easily decide which to use for various assembly and handyman tasks.

In terms of material compatibility

Some metal drill bits have protective coatings like titanium and black oxide, which make them compatible with various surfaces, including wood, metal, Polyvinyl Chloride (PVC), and fibreglass. 

However, a regular HSS metal drill bit isn’t suitable for drilling into masonry and other rigid materials since it’s designed for light metals and plastics. When working with such materials, you must look for a drill bit with a carbide tip, as the carbide material is more durable and has heat-resistance properties. 

Conversely, wood drill bits are only limited to hardwood and softwood since wood tends to dull quickly. 

In terms of point design

Most metal drill bits have a conical or split point design with an angle that varies from 118° to 135°.  A conical point design looks like a small sharp cone, and the purpose of this specific point design is to prevent the bit from “walking” or sliding away easily from the intended drill spot. This allows the user to drill holes more precisely.

On the other hand, wood drill bits have a brad point design. It appears as a small sharp point at the centre of the drill bit, which also functions like the conical point of a metal drill since it keeps the wood drill bit centred, helping the user drill precise holes. 

Other wood drill bit variations, like the auger bits, have a screw-like point tip. This point design creates deep, clean holes and makes pulling the bit from the wood easier. 

Remember that even though their unique point design makes drilling more efficient, the tip of a drill bit will get dull over time. It would be best to hire an expert who can provide tool sharpening services and help refine the edges of the drill bits. Doing this helps avoid damaging the material and the drilling tool itself. 

In terms of bit design and shape

Most metal drill bits are shaped like cones or cylinders. A cone-shaped metal drill bit has multiple diameter steps for drilling holes of different sizes. Meanwhile, those with a cylindrical shape usually come with spiral channels or flutes for drilling small and precise holes. 

On the flip side, wood drill bits have a pointed bit design with lips or cutting edges for precise positioning and drilling clean holes. Although some variations of wood drill bits have different bit design shapes (i.e., spade bits having a flat-paddled shape and auger bits having a screw shape), the pointed tips and cutting edges will remain the standard features of all wood drill bits. 

In terms of cutting speed

When measuring the cutting speed of drill bits, look into their revolutions per minute (RPM) or spindle speed to check how fast they rotate per minute. Metal drill bits typically have a lower RPM, which ranges from 500 to 2,000 RPM, to prevent the metal from overheating while drilling. 

As for wood drill bits, their average RPM ranges from 3,000 to 4,000 RPM. The cutting speed is higher because of the softer nature of wood. It doesn’t overheat, unlike metal drill bits. However, when drilling into hardwood, you may have to lower the cutting speed to 1,500 to 2,000 RPM to prevent the risk of burning the wood. 

Maintaining the correct cutting speed can be tricky, especially for beginners. So, if you’re unsure about this specific drilling aspect, consider seeking help from an expert handyperson. They can configure the drills for you, ensuring control and precision when drilling with various drill bits.

In terms of project suitability and ease of use

Wood drill bits are more convenient for assembly and disassembly projects involving wood. They come in a wide range of bits for different hole sizes and types and allow you to drill holes precisely with minimal wood splintering and tear-out.

On the other hand, metal drill bits are necessary for metal projects, providing high precision for various assembly projects, especially those involving metal fabrication. However, metal drill bits are less convenient than wood drill bits because, as we said earlier, they tend to overheat. So, properly cool the metal drill bits first and apply a slower drilling speed to avoid overheating. 

In terms of cost

Since metal drill bits are designed for drilling more rigid materials, the materials and technologies used to manufacture them are more advanced. For this reason, they are more expensive than wood drill bits. They cost approximately $2 per piece, while the most expensive ones are $2,679. 

Meanwhile, the price for wood drill bits per piece is the same since you can buy them for around £2 per piece. But when you buy them in a set, you’ll notice they’re still much cheaper than the metal bits, with the most expensive wood drill bit sets being only $199. 

Aside from the initial cost of each drill bit, you may also have to consider the cost of hiring a handyperson or carpenter. Drill bits, whether wood or metal, come in different types, so you may need the help of these experts when choosing and setting up the drill bits for the drill driver.

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