Why are drills Water Cooled?

Why are drills Water Cooled

Drills are amongst the most popular power tools used in many days to day applications. Amongst the first things I learned to do as a young handyman was how to drill correctly and precisely. I was surprised to note people use water onto the surface of drilling. I wondered why the drill had to be cooled by water.

Why are drills Water Cooled? A drill is water-cooled to prevent the drill bit from overheating. This helps increase the life of the drill bit while improving the efficiency and precision of the holes being drilled. And the water also helps in springing out the waste while drilling.

Water can be easily found anywhere, so people prefer water to cool down the drill bit. I’m sure you’re curious to know more about the same. I’m here to provide you with a few answers based on my experience with drills. Read on as I discuss other queries about drilling, including various drill bits.

A drill works primarily on the concept of friction. In this process, the kinetic energy of the piercing drill bit is converted into heat energy by basic physics. However, when drilling a hole, this heat has nowhere to escape.

As a result, there is a steady accumulation of heat in the hole, that is transferred through the metal drill bit, and the surroundings of the hole. And that heat in excess can have a negative impact on your drill bit.

Supplying water into the hole at the same time as the drilling process acts as an effective coolant. This helps cool the tip, preventing damage to the bit over long periods of drilling. The water can then flow out of the hole, along with some of the dirt, effectively allowing more heat to be removed. 

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Can drilling without water damage it?

There is a chance that not having a coolant like water being applied into the drilled area can result in damage to the drill bit. The bit can become blunt quickly. In the worst case, the bit can completely shatter.

The friction releases a lot of heat, which is then contained in the hole which is being drilled. The stresses on the drill bit increase as the bit goes deeper into the surface, requiring more power and generating more heat as a result. 

The lack of coolant will allow for the steady build-up of heat, while not having a proper outlet for it to escape. As a result, the bit will operate outside its optimum conditions, which will reduce the performance. This will also lead to faster blunting of the tips, which will drastically reduce the lifespan of the bit.

— Also read: Why are Brushless Drills Better than Brushed Drills?

In some extreme cases, under high amounts of stress on the bit, the increased temperatures can cause the drill bit to completely shatter, rendering it useless. It can also destroy the material you are drilling through and shrapnel from the shattered bit can cause damage to the motor of the drill.

Types of Drilling bits and their functions

Different types of drilling bits are designed for different materials. Other factors affected by the drill bit include the depth of the hole, the finish of the hole, and the maximum diameter. I have listed the different types of bits and their applications to help you select the right ones according to your requirement. You can read more about these drilling bits from this source.

  1. Twist Drill Bit

A twist drill bit is the most commonly used drill bit in household applications. This bit is capable of drilling through light metals, wood, and plastic. It finds its major applications in-home repairs, installations, and DIY projects.

  1. Brad-Point Bit

This type of bit is commonly used for wood-boring purposes. Thanks to its symmetric W-shaped tip, the bit makes a clean exit hole. It also has wider flutes to allow for a better evacuation of heat and debris from the hole.

  1. Spade Drill Bits

Spade drill bits are used in woodworking applications when there is a requirement for bores of a larger diameter. The central tip helps stabilize the drill, while the wider points at the end of the flattened blade allow for the bore to be created cleanly.

  1. Auger Drill Bit

An auger drill bit is used primarily in large woodworking applications that require a deeper penetration capability. Thanks to its central tip, the hole can be made without requiring too much effort. The hollow design allows for the removal of debris from within the hole in an effective manner as a result.

  1. Countersink Bit

If you need to use screws on wood without having the head stick out, then this bit helps solve the problem. The cutter at the top of the bit automatically widens the hole, accommodating the head as a result. 

  1. Step Drill Bit

A step drill bit allows you to bore holes of different diameters using a single bit in a stepped manner. This bit is primarily designed for thin metals, but can also be used in certain wood applications. This is especially useful to clear waste from the hole.

  1. Self-feed Bit

Self-feed bits are similar to auger drill bits, except that they do not have flutes. The bit has a central tip that positions the drill properly before guiding the rest of it through the wood. This bit is used in woodworking.

  1. Masonry Drill Bit

If you require a bit that can be used to drill through concrete, brick, and masonry, then the masonry drill bit will cater to your needs. Combining it with a hammer drill for the best results, this bit pulverizes the material to make holes through the material. The finish while using this bit is not very smooth, and is more suited for construction requirements.

  1. Forstner Drill Bit

A Forstner bit is used in woodwork based applications where one may have to bore partially through the wood. The wood beyond the hole will be flat and smooth. If completely bored through, the exit hole will be neat. This bit requires a lot of force and works better with drill presses.

  1. Glass Drill Bit

This type of bit is meant to drill through glass and other material that can shatter easily. It must be used with a rotary drill at very low speeds to ensure that the glass does not develop cracks and eventually shatter as a result.

And if you want to know more about all kinds of drilling bits then you can check out this detailed article by Sensible Digs, they covered all about drilling bit in their article.

Can drilling wood cause fire?

When you are drilling through any material, heat is generated as a by-product. However, wood has a lower ignition temperature. As a result, it is amongst the most susceptible to catch fire when the material gets overheated. 

Although it happens rarely, there is a chance that your wood can catch fire when being drilled through. The heat generated because of the friction can ignite the wood and the sawdust, eventually starting a fire.

However, the wood will not spontaneously ignite. The wood will start smoking or you will have burning embers, which means you should stop the drilling process immediately. If you continue drilling in this situation, then there is a high chance that the wood will eventually catch fire.

Can a drill overheat?

Many of us have the urge to finish the drilling process in one go. While it may seem like a good practice, it can do real harm to the drill itself. Not taking breaks while drilling prevents the escape of heat generated during the process. The drilled dust can also further aggravate the buildup of heat, causing overheating issues.

It is possible for your drill to overheat. The primary reasons why this could occur include continuous drilling, improper speed setting, blunt drill bits, and lack of a cooling system.

Another reason that is commonly overlooked is setting the speed of your drill. Different materials have different speed settings according to the type of material and the dimensions of the hole that needs to be drilled. 

Setting your drill speed too low could overwork your drill bit due to extra friction. This will force your motor to work harder, eventually causing the unit to overheat. If you set the speed too high, there is a chance you could end up burning the material you are drilling into.

Blunt drill bits are a major reason for drills overheating. A sharp bit can penetrate through the surface of the material much easier, reducing the stress on the motor. A blunt bit will require much more energy from the motor, eventually overworking it over extended periods of time. This is one of the most common reasons why drills face issues related to overheating.

The last reason why drills could get overheated is the lack of a cooling system. A cooling system effectively reduces the temperature within the hole by spraying liquid to absorb the heat produced. 

However, drills with a cooling system are expensive. In certain applications, the lack of a cooling system will cause your drill to overheat no matter. This will happen especially if the material is hard to drill through and your motor is not powerful enough.


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