As a DIYer, you may have to drill through materials like wood and plastic numerous times. However, when it comes to metal, everything seems daunting. Well, the good news is that drilling through metals is the same as drilling through any other material, with slight variations in the technique, that’s why in this post we’ll show you how to drill through metal.
So, given that you have equipped the appropriate safety gear, start off by sandwiching your metal workpiece between a couple of flat wood scrap pieces. Make a dimple on the point where you intend to drill, lubricate the workpiece, and begin cutting at a slow speed. Finish off by cleaning the drilled hole.
However, there is a lot more that goes into each of the steps mentioned above when you are using a handheld drill. Below, we will be diving deep into the details of each of these steps and more.
So, let’s get started!
Choosing the Right Drill Bit
The standard drill bits, also called twist bits, are designed for materials, like metals. However, to be sure that you are getting the right one, have a look at its tip; it should have a couple of flat cutting edges and not a protruding center point.
If it does have a center point, it is designed mainly for wood and will get damaged if used on metals.
Apart from that, you would want to consider the material out of which, your drill bit is made. Standard bits are made from four fundamental materials, high-speed steel (HSS), black oxide, cobalt oxide, and titanium.
Of these, the cheapest bit is that of HSS while the most expensive and durable is that of titanium.
Choose the HSS drill bit if you only have a few holes to drill on a thin metal whereas if you are looking to have a more durable bit at hand for any current and future tasks, especially on thick metal, a titanium drill bit is your choice.
It is also worth mentioning that if most of your drilling tasks are based on thin metal or sheet metal, you can opt for a step bit as well. It offers a variety of hole sizes and is mostly used by electricians. However, step bits are costlier than the standard ones.
Once you have gotten hands-on an appropriate bit, here’s what you need to know about drilling through metal:
- A powerful handdrill
- Appropriate drill bits
- A hole saw (optional)
- Flat wood scrap pieces
- A hammer
- A nail
- Motor oil or 3-in-1 household oil
- Drill press (optional)
Step 1: Take the Necessary Safety Precautions
When you are drilling through metal, small but sharp metal shavings are produced which can be a hazard to your eyes. Therefore, you need to take the necessary safety considerations beforehand.
For starters, equip leather gloves, safety goggles as well as a face shield.
Apart from that, do not forget to clamp your workpiece. This is because sometimes, the drill bits can dig into the metal and stop in the middle as a result of which the spinning motion of the drill gets transferred to the workpiece.
Step 2: Utilize the Sacrificial Sandwich Technique
Grab a couple of scrap flat pieces of wood and sandwich the metal workpiece between them. As a result of taking this step, you will be able to drill a clean hole into the metal.
Step 3: Making a Pilot Hole
When drilling through a metallic surface, it is quite common for drill bits to go off track so it is recommended that you bore a dimple or a pilot hole in the metallic workpiece.
Accordingly, measure and mark the exact location where you want the hole and then, using a hammer and a nail, make a tiny hole in the workpiece. As a result, when you are drilling through the metal, it will make for a much cleaner and smoother hole.
Step 4: Oil the Workpiece
When you are drilling through the metal, a lot of friction is created, which in turn, results in heat generation. This heat damages both your drill bits as well as the metal workpiece you are working on.
So, accordingly, before you start the drilling process, be sure to add a few drops of oil to the workpiece to minimize friction and the resulting damages.
Note that if you are boring a much larger hole, you may need to lubricate the workpiece again. Also, lubrication is necessary for only the thicker metal sheets, like steel that is 1/8 inch or more. For thin metals, such as Aluminum and Brass, you may not need to lubricate after all.
Step 5: Go Slow
When drilling through metals, you need to make sure that both your speed and the pressure you apply are low. Otherwise, your drill bits could get dull quickly.
Larger drill bits and thick metals like steel require slower speeds as compared to the smaller drill bits and thinner metals. For instance, for a small drill bit of around 1/16-3/16 inches, you can use a speed of around 3000 RPM whereas, for a larger drill bit of around 11/16 to 1 inch, an RPM of under 1000 is recommended.
As a general rule of thumb, go with almost half the maximum speed of the drill you are using. As for the pressure, just keep it moderate.
Step 6: Start with Small Drill Bit
When you are starting out the drilling process, it is worth keeping in mind that large drill bits, due to their large surface area, have a hard time drilling into the metals. As a result, the process can be time-consuming.
Ergo, to increase the pace of the proceedings, use a small bit to start with and then, move incrementally with your drill bit size until it corresponds with the desired hole size.
Furthermore, when you need to drill larger holes in thin metals, you can also resort to a hole saw for clean and quick work. However, be sure to use a sandwich your workpiece when using a hole saw as well.
Step 7: Be Wary of Smoking
If you notice crisps of smoke coming out of your workpiece, it means that you are drilling too fast which is in turn, resulting in excess heat generation.
So, immediately stop, allow your drill to cool down, add some oil to your workpiece, and resume. However, make sure that you dial down your speed a notch this time around.
Step 8: Clean Up the Hole
Once you are done drilling, the resulting hole may have rough edges. So, to make them smooth, you need to clean them up.
Accordingly, choose a drill bit a little larger than the diameter of the hole and set it in the hole. Now, twist it with your hand and all the undesirable metal shavings will be scraped off.
However, if you would rather prefer to use a fancy deburring tool, feel free to get yourself one.
Using a Drill Press
If you are a handheld drill user, you may relate to how easier it is to use the tool. However, in terms of accuracy and output, a drill press always seems to have an edge over its handheld counterpart.
This is because drill presses are normally made with the objective of metalworking in mind and everything is controlled by the machine as a result of which, more precise holes result.
Frequently Asked Questions
What Color Drill Bit is For Metals?
The cheapest drill bit for metals is made from HSS and is colored black whereas the best metal drill bit is coated with titanium and is colored black.
What Kind of Drill Bit Do I need for Aluminum?
As mentioned before, an HSS drill bit is ideal for thin metals like Aluminum.
And there you have it – a complete guide on how to drill through metal; we sincerely hope that it addresses all your queries regarding the topic under discussion.
To reiterate, choose the right drill bit and equip the appropriate safety gear before commencing with the drilling process. Then, employ the sacrificial sandwich technique, oil the workpiece, and start drilling. During the process, be sure to go slow and stop if you observe smoke coming off. Finally, clean up the hole to finish the job.