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7 Tips on How to Drill and Tap Hardened Steel

By: David S. Miles | Last Updated: January 19, 2024

A lot of drilling tasks are always on the go-to list of a mechanist. And sometimes the task does not involve wood but robust steel material. No doubt, methods of drilling won’t be the same. Because here you sometimes need to go through a lot of tapping as well.

Drilling and tapping such hard materials seem easy at first. But when you actually get into the job, there’s a lot that comes to your attention. A little mistake might need up getting a wrong hole. Sometimes, it even causes personal injuries. We don’t want that.

And so, let’s talk about some tips on how to drill and tap hardened steel that experts swear by…

How to Drill and Tap Hardened Steel Using 7 Tried & Tested Tips

how to drill and tap hardened steel

So, what are those tips that will get you that smooth steel drilling result eventually? Keep on reading!

The Ideal Type of Bit Selection

For obvious reasons, drilling a metal will be way harder than drilling through wood. And that’s why there’s a need to choose tougher drill bits for hardened steel. To test out whether the bit you own will be suitable for drilling, check if it tapers to a point. In case of that, the sign says it’s not right for steel drilling.

You will find cobalt bit in any hardware or local store and even online that are specifically designed for steel. Just make sure the cobalt has a high density. It needs to be a high-speed steel type.

This means the bit is capable of cutting through very hardened steel material. Also, these come with tungsten or molybdenum alloying. This means the quality is very high and almost unbeatable.

Carbide tools are the most suitable answer if you are someone who needs to do frequent drills and taps on steel.

Keeping the Heat Under Control

Heat is probably not good news when you are drilling hardened steel. And so, you need to apply a few drops of oil on the metal. This will help to keep lubrication affecting the working drill bit. As a result, there will be less heat production going on overall.

You also want to make sure your drilling speed is not very high. A slow and gradual drilling process will eventually reduce overheating chances. Also, a coating of titanium nitride on the bit will make it more resistant to heat. This will help in withstanding high feed rates. Also, it helps with superior hole integrity and better finish.

Follow Some Common Ethics

There are often pretty unsatisfied results with steel drilling because of the dull drill bit. To avoid that issue, bring a woodblock on the spot. You want to place it below the metal. That’s it, there will be no chance of drill bit penetrating through the metal and hitting working surface.

When you want to make a drilled hole larger, use emery cloth. You need to fold the piece of cloth into half. Make sure the abrasive sides are facing inward. Now let it sit over the hole. Through this, you will be able to avoid the noise level while working. Also, there will no chance of a jagged hole. Go ahead with your wider drill bit and the hole will be smooth and nice.

Controlling the Vibration

There can be huge problems with evacuation, formation, and chip breaking when you are working with steel. Since they come with a generous amount of strength and elastic. The chips clogged will result in tool failure.

It also makes the workpiece vibrate too much. And that can affect the hole’s finish. So, make sure the piece is stabilized using a tool holder. This will reduce the vibration of the tool dramatically.

Sharp Tools & Correct Feed

For heat reduction, good result, and controlling the vibration, there’s this one tip that works as an ultimate solution. And it’s using sharp tools.

A correct feed and speed are the perfect solution to cut clean holes when tapping on steel. With a drill bit that has a narrow diameter, you want to maintain the minimum speed.

However, when it comes to using wider ones for bore deeper holes, back dialling is the answer. This will reduce the breakage chances a lot. Try to still maintain the SFM rate. Depending on what steel grade you are working with, the speed and feed parameters will vary.

Let the Tool Cool Down Constantly

When you are working with the drill, stop every now and then. Let it cool down for a while. Overheating can also be resultant from non-stop operation. So, you want to keep each drilling session short. At the same time, you have to maintain an adequate amount of pressure.

Never Risk Your Safety

how to drill and tap hardened steel

Okay now when you are on with drilling the steel, don’t forget to get safety precautions right. No matter what material you are working with, drill bits have a horrible habit of snapping.

This literally throws those metal shards towards your eyes. And so, anybody near the drilling process including you need to wear proper safety glasses no matter what.

Also, you need to be careful when the drill tip starts to come through the bottom of the hole. There’s a good chance it will snag the metal. And also, it will spin the drilled piece.

This can happen with considerable force. And that will eventually cause a cut on the person working. Sometimes the case even leads to breaking bones. So, make sure you clamp the piece religiously while drilling. The surface needs to be substantial as well.

Wrap Up

That’s all folks! Here you have seven fantastic tips on how to drill and tap hardened steel with amazing end results. Do apply and utilize these ideas into your regular working life. Through learning and working with such tips will eventually make your projects end in a better way and also much faster. Good Luck on Whatever Project You Are Working On!

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One thought on “7 Tips on How to Drill and Tap Hardened Steel

  • Thanks for the info about drilling. My friend is doing research on rock drilling. I’ll share this info with my friend as he looks for a way to handle drilling for a project he is planning.

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