What Speed Should I Drill At?

Figuring out RPM speed for your drill can be very confusing. Sure, there are recommended drilling speeds all over but they seem to vary from place to place. Instead of creating another chart for you with our recommendations, we want to actually teach you a bit about why we should drill at different speeds for different circumstances. Knowing this information, we can create a determining drill RPM best practice guide.

Drill Bits

The goal of most is to balance the life of a tool (drill bit) and the speed of the drilling(RPM) while not compromising the material. This is often how the optimal RPM is found.

We know that not everyone is looking for this cross point however, you may want to save money by burning through less drill bits or get a job done more quickly by speeding up the drilling pace. With the following considerations you will be able to determine what direction you need to move in to get the job done how you need it to.

Speed

The first thing to consider is speed (RPM’s) of a drill bit. When drilling into a harder material the general practice is to go slower. As the bit turns it begins biting or cutting into a material. This causes friction which will heat up the material and the drill bit. If the material begins to show signs of discoloration or smoke there is a good chance that the drill bit is creating too much friction which, in turn, will cause the material to overheat. This over-heating will result in a warped or damaged material and a quickly spent drill bit.

We can look at the graph to the right for a visual representation of how this effect works. As you can see when our RPM (speed) decreases the life of the bit will be extended. Most manufacturer recommendations will attempt to find the best compromise here while someone who recommends speeds to save drill bit life will obviously aim lower. We also recommend using drill bit lubrication for metal-cutting to extend the life of your drill bit.

Size

Another factor to consider is the size of the drill bit. A larger drill bit has far greater surface contact per revolution when compared to a smaller one. This means that a larger drill will generate more friction per revolution as well. So while it is perfectly fine to use a small bit at a higher RPM in a material, you may notice the larger bit causing some of those warning signs we talked about earlier. If this is the case, simply slow down and let the bit do the work.

Drill Bit Function

Different drill bits are specially designed to cut through different materials. This can be done either by altering the design of the bit itself, making it from a harder material, coating it or just adding a stronger tip to the bit to make the initial cuts. Making sure you have the proper bit for material is also incredibly important.

Material

The other consideration you will need to factor in while drilling is the material you are drilling into. If you drill at the wrong speed your bit will cause the material to heat up and can actually change the properties of the material you are drilling into. You can also ruin materials this way such as burning wood.

Hardness

The hardness of a material is the consideration you should make when beginning to work on it. Different materials have different hardness and as a result, different temperaments to heat and drilling. Choosing the appropriate bit for the material can cut down on wasted bits and damaged materials.

Outcome?

So now that we know all of the different factors that should be considered when drilling, let’s come up with an order of operations for determining the best drill speed for you.

*Note: This is a very generalized overlook of how materials can react to different temperatures caused by friction.

Determining Drill Speed

1. Identify the material you are using.
2. Find the appropriate drill bit suited for your material.
3. Determine the size of the hole you need to drill into the material.
4. Decide what is more important: getting the job done faster or preserving the life of the drill bit.
5. Begin on a slow RPM setting and test out the bit.
6. ALWAYS (especially at high speeds) pay attention to the material.
7. If the bit is cutting fine and you desire a faster pace simply increase the RPM of the drill
8. Adjust as necessary.

Considerations

• Watch for discoloration, smoke and bit chipping as these are all signs of drilling too quickly.
• If it is your first time drilling into a material, always drill slowly and work your way up to the speed you want.
• This method will take some practice to find comfortable ranges have fun with it do some experiments.
• Keep a notebook on hand so you can record your findings and keep your own recommended drill speeds on hand.
  • You can also record other information in this notebook such as which bit and size you used etc.

---

Power Drill Adjustable Slip Clutch / Torque Control

Power Drill Adjustable Slip Clutch / Torque Control Transcript Scroll Down To Continue Reading Bob: Welcome back to Albany County Fasteners – Fasteners 101. I’m Bob and today I want to demonstrate to you a clutch that’s built into your drill. Basically, you have a clutch on the head of your drill that goes anywhere from a number one up to, at least on mine, is a number 15. Okay, and then you have what they call drill mode and it has a little drill bit there so there’ll be no slippage. So I want to show you so you don’t over-drill your product into your material. Now that could be into steel, it could be into to wood, or finish materials so you don’t dimple the wood. Right now, I have set this to a number ten on my drill. I’m going into a piece of 2×4 pine and once the screw starts to hit the face of the wood, the clutch in here will start to slip and I just want to demonstrate this to you. I’m going to start it now and you get no resistance as far as driving it in but once it hit, the clutch slips and it stops the drilling. It doesn’t go any deeper into the wood. Now if you wanted to drive that in less you would put the clutch at a number, let’s say number eight or number nine and then obviously the clutch will start to slip even more. However, as you’re driving if you would have set this to a number one then when you get about half way in the clutch is going to start to slip and you’re going to stop driving the screw in and you’re going to have to readjust the clutch. That’s your quick tip for today. Thanks for watching.