When it comes to drill bits, two common types include metal drill bits and wood drill bits. As you can tell, one type is designed to drill into metal, whereas the other is designed to drill into wood.
That said, you might be wondering whether metal and wood drill bits are interchangeable. Today we’re going to talk about all of the main differences that you need to know between metal and wood drill bits.
Similarities of Wood and Metal Drill Bits
Although there aren’t many similarities between the two, there are some basic similarities between wood and metal drill bits worth noting.
1. They’re Both Drill Bits
Of course, the most basic similarity shared between these two things is that they are both drill bits. Both wood and metal drill bits are designed to drill holes into the respective materials as indicated.
2. They Can Be Used with Various Tools
Another similarity shared by both metal and wood drill bits is that they can be used with various tools. These are interchangeable bits that you can use with normal drill drivers, hammer drills, milling machines, and drill presses too. The exact bits that you use will depend on the machine in question, especially in terms of the size.
3. There Are Many Types of Both
This is something that we are actually going to leave for the section on differences, but a similarity shared between these two things is that there are many types of wood drill bits and metal drill bits that serve different purposes.
Differences Between Wood and Metal Drill Bits
Now that we know what makes wood and metal drill bit similar, let’s figure out what makes them different.
1. Shape and Design
One of the most basic differences here is that a wood drill bit has a very small spur or extremely sharp point in the center. This is designed to penetrate the wood, with the main goal being to keep the drill bit stable and centered. This is generally a defining feature of all wood drill bits.
On the other hand, a metal drill bit has no such spur at the front. A metal drill bit features a conical cutting tip that is then followed by spiral-shaped flutes. This is the number one main difference that makes each of these drill bits ideal for their respective materials.
2. Material
Although wood and metal drill bits may on occasion be made out of the same materials, metal drill bits do need to be much harder and denser so they can drill into a much denser and harder material. Drill bits designed for wood are usually made out of something like high-speed steel, cobalt, or carbide.
Metal drill bits are usually also made out of these materials but are then coated with additional materials to increase their durability. To increase their durability, many metal drill bits are coated with black oxide or titanium.
3. Force Required
Because wood is quite soft, and due to the shape of a wood drill bit, you don’t need nearly as much force to penetrate into the wood as you do with a metal drill bit. Simply put, metal is much harder and denser, and due to the shape of the metal drill bit, much more force is required to penetrate the surface.
4. Staying Centered
One of the biggest advantages that you get with a wood drill bit is that center spur, which helps to keep the drill bit centered. A metal drill bit has no such spur, which can make it hard to keep a hole centered and properly aligned.
5. Heat Generation
Going back to the material that these bits are made out of, metal drill bits usually need to be coated in some kind of extremely hard and dense metal due to the fact that drilling into metal generates a lot of heat. Drilling into wood doesn’t generate nearly as much heat.
6. Main Purpose
Of course, the main purpose of a wood drill bit is to drill into wood, whereas the main purpose of the metal drill bit is to drill into metal.
7. Types of Bits
What you then also need to consider is that both wood and metal drill bits come in many different types.
With wood drill bits, you have brad point bits, spade or paddle bits, auger bits, installer bits, Forstner bits, and hole saw bits. With metal drill bits, there are twist drills, step drills, and center bits.
How to Identify a Metal Drill Bit
One of the main ways to differentiate between a metal drill bit and a wooden drill bit is by looking at the tip. Now, this will depend on the type of wooden drill bit, but the vast majority of the time, wooden drill bits will have that spur at the front designed to keep the bid centered, also known as a brad. Metal drill bit usually has no such spur and generally has a much more conical tip.
The other main way to differentiate between wooden and metal drill bits is by looking at their color. Wood bits usually aren’t coated in everything, and generally, just have a silver color. On the other hand, metal drill bits, due to being coated in cobalt, black oxide, or titanium, are often copper or golden colored, as well as dark gray or black.
Are There Any Drill Bit Types That Can Be Used on Both Wood and Metal?
If you have a drill bit made out of high-speed steel, carbide, or cobalt, and it is then also coated in cobalt, black oxide, or titanium, it is designed for metal, although you can technically use them for wood as well. Moreover, in terms of types of drill bits, one of the only ones that you can use for both wood and metal is the step drill bit.
Can You Use a Metal Drill Bit on Wood?
If you only have a metal drill bit handy, but you want to drill through wood, it is technically possible. For one, a metal drill bit is definitely more than hard and solid enough to make its way through wood. Wood poses absolutely no risk of breaking a metal drill bit.
With that being said, a metal drill bit usually never has that spur at the front, which can make it somewhat difficult to keep the drill bit centered. The drill bit may wander a little bit when you go to drill into wood. Although, with a good bit of force, and some practice, it should be doable.
Can You Use a Wood Drill Bit on Metal?
On the other hand, when it comes to using a wood drill bit on metal, this is something that you really can’t do. The simple reality is that a wood drill bit is not going to be hard enough to make its way through metal.
Chances are pretty big that you will end up snapping the wood drill bit when you try to drill through metal. This is especially the case when it comes to that thin and sharp spur that is usually on the front of a wood drill bit. Wood drill bits aren’t designed to handle the massive amounts of heat that metal drilling generates.
Summary
You should now know all of the relevant differences between wood and metal drill bits.