Why Does a Drill Bit Hot? – Top 09 Reasons

A drill bit is hot due to poor cutting edge and angle, using a wrong drill bit, using a high RPM, applying more thrust, drilling with no cutting oils, and inner clogging due to swarfs. It will help if you use a proper drill bit with recommended RPM rate and cutting oil to reduce the drill bit heat.

If you are not able to reduce heat generation, the drill bit can be heated rapidly. Finally, it will be overheated and melt. This kind of action happens in hard materials mostly. In order to protect the drill bit, you had better read all reasons and avoid the drill bit heating. So keep reading until the end.

1. Improper Cutting Angle

118 and 135 drill bit angles
Right Drill Bit Angle

Every drill bit has a cutting angle. The cutting angle is really important for the drill bit. When there is a proper cutting angle, it can easily cut and remove the material. When it is reduced, it will slipper the surface. When the surface is slippering, it can generate more heat due to friction. The final result is a highly heated drill bit.

Normally Soft materials such as wood and aluminum need a 118-degree cutting angle, and hard materials such as cast iron need a 135-degree drill bit. If there are wrong drill bits, it will take much time, and both drill bit and drilling machine can be heated more and more. When you drill cast iron this guide will help you.

If there is no proper cutting angle, you can sharpen it.

If your drill bit is already hot you can use these 07 Tips to Cool the Drill Bit.

2. Blunt Cutting Edge

Blunt Drill Bit

The cutting edge can be damaged due to abrasion. Some times steel parts, nails can be remain in the wood pieces.

When we drill through steel using a wood drill bit, the bit can be damaged easily. Hence it can be blunt and dull easily.

The Blunt drill bit end is not linear. There is a wavy and dull edge. Hence these edges are not able to cut and remove the materials continuously. Because of this reason, tool can be slippered on the material, and heat is produced badly. As a result of this drill bit will be heated.

Read More About – Top 08 Drill Bit Problems and Solutions

3. Select a Wrong Drill Bit

When you select a drill bit for wood or metal, it is really important. You must select a drill bit it is compatible with the geometry, coatings, and manufactured material.

Imagine you use a masonry drill bit for steel drilling. It is an impossible task. Wood drill bits are made for cutting lower-hardness materials. when using a wood drill bit for metal, definitely drill bit will oveheat.

When you drill any material, it should be lower in the Rockwell C hardness scale than the drill bit hardness value.

4. Use a Higher RPM

Normally most material has a recommended drilling RPM to increase the efficiency of the work. If the RPM is high, it will affect the tool performance.

When the tool RPM is high, it touches the surface at a higher rate. Due to this, drill bit can be heated.

Normally wood drilling requires high RPM, and Steel, concrete, stone, brick, and glass requires less RPM. when the drilling material is tougher, its heating amount is high.

5. Too Much Thrust

When we drill, we must apply constant force. Normally this force is a thrust force. When we thrust, it should not be too much. When the thrust is high, its cutting amount is trying to increase. Due to this, the tool produces more torque, and finally, the drill bit and the drilling machine are both heated unexpectedly.

We should not thrust much into the drill while the chips are removed in a gentle way. That is the sufficient force you should apply to the drill.

When you use bench drills, this can happen mostly. You can apply more force when you use the bench drill, and the heating also highly affects the bench drill.

When you see smoke from the drill bit with the cutting oil, it is probably due to heating. Hence do not thrust much during the drilling process.

06. No Cutting Oil

While you drill hard material, you should use the cutting oil. Cutting oil acts as a lubricant as well as heat transfer. When you drill steel, you must use the cutting oil. If you drill without cutting, drill bit can be easily overheated.

Good cutting oil should have high thermal resistance and lubricant properties. Due to this, many ingredients have been added to the cutting oil in order to increase the thermal resistance and lubricants,

Can I Use Water as Cutting Fluid?

Water boils at 100 °C, and there are no lubricant properties. When water is using a long time, there will be rusting due to interaction with the atmosphere. Due to this, water can’t be used as a cutting oil for steel.

But it can be used for the glass, tile, and concrete drilling process in order to prevent dust and improve thermal conduction.

7. Combined Materials

This is a common issue. When we drill into the wood, there may be part of the nail inside. When there is drilling, it can break the drill bit easier if we continue the process.

So before you drill, make sure there is no additional material inside.

9. High Environmental Temperature

Environmental temperature badly affects the drill and drill bit. If there is more temperature in the environment, the generated heat can leak into the environment. More than that due to these reasons your drill can be overheated.

So it tries to heat. If you use the cutting oil, this can’t be resolved. You have to stay at a low-temperature area before you start the drill.

10. Inner Chips Clogging

When you drill, you can see chips are coming out. It can be varied with the drilling speed. If there are no cutting oils, wet condition materials can clog these swarfs inside easily. When the swarfs clog inside, they generate more heat. So drill and drill bit will be heated.

Normally you must keep 2 times drill bit diameter flute length from the top of the drill. So removed chips can be moved out easily.

You can use cutting oil to prevent inner clogging. Cutting oil has lubricant, and it will easily remove the chips to the outside. And also, do not drill wet woods. Those are clogged easily. If you drill them, do them step by step. Push and pull drilling method.

Tom Mackency

Tom Mackency

Hi, I am Tom Mackency. It has been 10 years that I have been working as a professional woodworker since 2013. I am really enjoying my carrier by creating many kinds of projects in my workshop. But mostly I like for home improvement projects. Home improvement and DIY projects are the most interesting things for me. More than that, the coolest things are power tools. Those are very precious and efficient than a decade ago. So I try to introduce so many things about power tools, woodworking, DIY projects, home improvement and many more interesting topics here.