How To Drill Into Metal (& Avoid Overheating)

Drilling through metal appears scarier than it is. Despite being a tough and resilient material, you will need fewer specialist bits that drilling through tile or minerals like quartz. If you’re lucky, you might even have bought a drill bit that is perfectly capable of going metal when you bought your drill in a set.

Drilling through metal is generally little more than some good technique and a good, general-purpose drill bit. Metal can take some beating, but it is a very drill-friendly material. If you know how to use a drill properly, you shouldn’t struggle.

Because metal can heat up and shards can be serious health risks, safe practice is really important. I’m going to walk you through how to drill into metal quickly, safely, and without breaking the bank.

How To Drill Into Metal


Gathering Your Equipment

Drilling into metal is more about technique than specialized equipment, but it’s good to be prepared. Setting yourself up right from the beginning is the best way to stop silly mistakes halfway through a job.

As you should have most of these materials to hand if you do drill work with any regularity, there’s no need to go and buy anything particularly specialist. If you are missing any pieces, you can pick them all up for cheap from any good DIY or hardware shop.

As we go through how to drill through metal, I’ll suggest a few specialist pieces of equipment. If you want to try out a few fancy techniques, you might want to pick these up when you have time. But for simply drilling a hole into metal, here’s a quick list of everything you’ll need.

  • A piece of metal
  • A drill
  • A drill bit that can work through metal (generally sold as metal – wood drill bits)
  • A second drill bit that is larger than the first (or a deburring tool)
  • Clamps
  • A punch
  • A workspace to place the metal on (such as a sawhorse or a workbench)
  • A lubricant like water
  • Appropriate safety gear such as goggles and a dust mask

Unless you want to do something specialized, these tools will give you everything you need. Helpful tips will be in this article for cutting out some steps with new pieces of equipment.

Safety First

Although drilling into metal isn’t difficult, it can be dangerous. You have spinning metal touching a possibly flat surface. This could cause the drill to spin-off, potentially leading to an injury.

You have metal shards coming out of the hole. This could cause damage to your hands or face. You have metal absorbing heat and getting very warm, very quickly. You could get a burn without proper care.

Safety always comes first. As you are working with metal, you should be wearing goggles to protect your eyes, a dust mask to protect your lungs, and fitted gloves to protect your hands.

As metal shards can be spat out from the metal surface, you want to wear goggles. Getting tiny pieces of metal stuck in your eyes can lead to long-term problems, including blindness. Take care of your body and you will have a much longer career.

Similarly, fast drilling can cause (what are effective) metal fillings into the air. Getting metal into your lungs can lead to lung problems, both short-term and long-term. Besides, it will also be painful. Don’t take chances with your health.

Some people choose not to wear gloves when drilling into metal. If you are experienced and know what you are doing, that’s fine. (Then again, you probably wouldn’t be reading this article).

Gloves protect you against injury from the drill itself, metal shards, and any heat that builds up on the metal. Wear fitted gloves as loose ones can get caught in moving parts.

Getting The Right Drill Bit For Metal

Most drill bits can deal with metal. Metal bits are designed for metal, wood, and plastic. If you have one of these bits, you can use it for metal too.

Not a lot of people know how to drill through metal. Although, the process isn't that hard, and it's easier than drilling through the tile, a lot of people still try to avoid drilling through metal.

The only difference will be how long they are expected to last. A high-speed steel (HSS) bit is excellent for metal.

These are generally lower to medium quality bits, so they might not last long. They will become dull after a few uses, so you might want to use something a bit stronger.

Titanium nitride bits are the best that are available right now. If you need something that will last you for a long time, you will want TiN bits. Manufacturers of these bits claim they last up to six times longer – they don’t heat up as much and they deal better with friction. If you plan to work with metal a lot, get some of these fantastic bits.

Prepare The Metal

Before you even start to drill, you need to prepare your metal. Unlike metal or plastic, you cannot hold a piece of metal by hand. Do so is dangerous for two reasons:

  • It’s more likely to kick back, possibly meaning your hand will go near the spinning drill bit
  • Metal heats up, meaning that you risk the chance of a burn injury

Use clamps to hold the metal in place. You should have at least two clamps holding the metal, but you can have more if you want. The most important part is keeping the metal as secure as possible while you drill.

When it is secured, find where you want to drill. Using a punch, make a small divet into the metal. Because metal is a very non-drill-friendly material, it will slip without a divet. The divet gives your drill bit a place to sit so you can start the hole.

When you have got your metal clamped and there is a divet, place your drill over the metal. Using moderate pressure and a slow drill speed, start to drill into the metal. Moderate pressure doesn’t mean light – if you are too light with the drill, you will cause the bit to slip and slide off the mark. This leads to danger, so avoid it.

Start Slow Drilling Metal

Slow drilling is almost always the best idea with metal. Yes, it takes longer, but you don’t need to worry about heating up the metal, ruining your drill bits, and potentially ruining the job. Heat can be dangerous, but your bits will also wear down quicker, wasting money and wasting time.

Rely on your clamps and keep both hands on the drill. You need to keep the pressure steady and consistent throughout the process.

If you feel the metal or your drill heating up, take a break and apply a lubricant to both. You can buy specialist lubricants, but water works just as well. The important point is to cool down the metals and not starting again until it is cool will save your materials.

As you go through the metal, make sure you are as slow at the start as when you finish. If you are too fast on exit, you can cause more sharps edges (also called burrs) on the opposite side of the metal. These are easy to sort, but it’s even easier just not to have to deal with them at all.

Deburring Your Hole

If you have made a clean hole into your metal, you may be able to skip this section. But if there are sharp edges or burrs on the metal plate, you will need to deburr it.

There is a whole range of deburring tools available at various prices, but you probably already own a perfectly fine piece of deburring equipment. A drill bit of the next size up.

Using a slightly bigger drill bit, hand spin it in the hole. As it is larger, it will pick up the burrs and smooth over the surface. Hand turning is important here. If you use your drill to work it, you will probably just start to drill a bigger hole than you need and get even bigger burrs.

Make sure your hole is smooth and then the job is done.

Related Read — Drill Presses Review

Drilling Large Holes Into Metal

If you need to drill a particularly large hole in a piece of metal, start with a small hole and progressively use larger drill bits. This will take the pressure off the metal and give you a clean finish.

If you start with a drill bit that is too large, you will cause stress to the metal. You are unlikely to break it outright, but it will heat up. More heat means more damage to your bits, so try to avoid it wherever possible. Even using a good lubricant will still cause more damage to drill bits due to the excessive friction.

If you want to do this as quickly as possible, you can use a step bit. Step bits look a bit like spinning tops and they are tapered from thin to wide.

You can use one step bit to drill an initially small hole that expands as you drill in. Using a step bit requires a bit of practice – it’s easy to over drill and end up with a larger hole than you need. Practice on a few pieces of scrap metal or wood before using your step bit.

Conclusion

Drilling through metal is easy. You need to prepare properly and take your time with the metal to get a good finish. Rushing the drill will cause damage to the bit, so don’t do it.

Gentle, consistent speeds will help you get good, clean holes in metal, and help your drill bits live to fight another day.

Remember safety first too. Metal can be dangerous, both at the time of drilling and years later. You don’t want to get burned by heated metal, get metal fillings lodged in your skin, or have small shards of metal in your lungs. Proper safety equipment is incredibly important with metal if you want to have a long and successful career as a metalworker.

FAQs About Drilling Through Metal

Is Drilling Into Metal Dangerous?

Yes, if you’re not prepared. Using the appropriate safety equipment will give you excellent defenses against the dangers of metal and turn any metalworking job into a quick, harmless process.

Do I Need Specialized Drill Bits for Drilling Into Metal?

No, you can use a general metal – wood – plastic drill bit. Finding drill bits that are specifically designed for working with metal may last longer, but they rarely offer much more of an upgrade over standard bits.

Do I Need to Use Lubricant When Drilling Small Holes in Metal?

You usually will have to, yes. Metal heats up quickly, so lubricant is always handy. Because smaller drill bits have a smaller point of contact, they are less likely to build up as much heat as a larger drill bit. Still, they will build heat that can damage your drill bits. Keeping the surface cool is key to maintaining drill bits for more than a few uses.

Can I Drill Into Thick Pieces of Metal With a Normal Drill Bit?

Yes, but you will need plenty of lubricants. As the piece is thicker, make sure it is secure properly. Using a lot of lubrication, drill into the metal in small sections. Ideally, you want to drill for no more than a few fractions of an inch at a time. Take the drill out and check the heat regularly.

Do Different Kinds of Metal Need Different Drill Bits?

You can often get away with using the same drill bits for all drillable metals, but tougher metals and alloys will need tougher drill bits. If you use weaker bits on steel, it might not last very long.

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