Metal Core Drill Bits: Types, Sizes, Methods of Application

Metal Core Drill Bits: Types, Sizes, Methods of Application

Metal core drill bits used for drilling round holes in steel, non-ferrous metals and other high-density materials. The metal core drill bits has the form of a hollow steel cylinder with teeth (with solders made of especially strong alloys) along the working edge and the landing connector on the opposite side. For more precise drilling, centering drills are used. Such a drill can be purchased complete with a crown or purchased separately.

All metal drill bits are designed to make holes of various diameters.

Characteristics important for the selection of metal core drill bits

The difference in the types of crowns occurs according to the following parameters, on which their specificity and working conditions with them depend.

  • Material – bimetallic core drill bits for metal , for example Irwin are in the greatest demand. They are made of two types of metal: the main cylindrical part is made of one metal, and the soldering along the working edge is made of another, denser metal (defeated). This design allows you to apply a minimum of effort during operation – the holes are smooth and accurate. In addition, bimetallic crowns wear out much more slowly.
  • Diameter – you need to consider first of all when choosing a metal bit for a drill. First, you should decide what diameter holes to drill. And then proceed from this data and select a certain size crown. Our site presents a wide selection of models with diameters from 14 mm to 177 mm.
  • Center drill – facilitates work, helping to drill holes more accurately in the place you need. In our online store you can buy metal crowns with a centering drill in a set, for example, in a set of Bosch 2608584812x, as well as single products like Enkor 24368
  • The number of crowns in the set – affects the amount of work. If you need to perform several operations in a domestic environment, then one crown for metal of the diameter you need will be enough. If you have a wide range of diverse works, then you should take care of the necessary equipment for your drill and purchase a set. On our website you can easily pick up and buy both a single tooling and a kit consisting of 10 parts, like Bi-Metal Enkor 24558.

In addition to various diameters changing inside the kit, a special adapter can also be supplied. It is especially useful when you need to use equipment with a shank type that does not match the type and size of the drill chuck.

Core drills
Core drills used to process metal products are also known as ring cutters.

The price of the product depends not only on the above parameters, but also on the manufacturer. On our website you can buy crowns from the most popular manufacturers known for the high quality of their products: Bosch, MATRIX, FIT, Irwin, etc.

Carbide core drill bits for metal: good quality and affordable price

Despite the rather narrow scope of use of crowns, it is practically impossible to find a precise and clear classification of them. Labeling products, manufacturers resort to their own definition of differences. And the names can be used different: “core drill”, “crown”, “circular saw”, “circular mill”. And this is not the whole list.

The division into species based on the characteristics of the material of manufacture is even more complicated. The designation “20 mm alloy steel crown” is true, but gives absolutely no idea about the product. All crown nozzles for metal are made of steel. Any steel has additives, that is, it is alloyed, supplemented with components that enhance or change its physical characteristics.

Carbide core drill bits for metal
Carbide core drill bits for metal are used both in everyday life and in large-scale construction

The most common wording is “high speed steel crown”. Such steel belongs to the high-alloyed types, it necessarily includes the following substances: tungsten – 19%, vanadium – 2.6%, molybdenum – up to 3%, chromium 3.5-4.4%. Such a combination of components makes the cutter durable, resistant to wear for a long time, red-resistant, that is, not subject to deformation at temperatures up to 600 ° C.

Carbide-tipped crowns from such a material are widely used; they are used both in everyday life and in large-scale construction.

Products are of good quality and reasonable price. The average size option – a crown for metal 50 mm – will cost (depending on the manufacturer) from 8.63$ to 14.38$.

Bimetallic core drill bits for material features and method of application

Bimetal – made of two types of metal. In the case of metal crowns, this is a combination of high speed steel and cobalt, the content of which should be at least 8%. In this combination, the material acquires the qualities necessary for effective cutting of various types of metal, including stainless steel, aluminum, copper, brass, etc.

Bimetallic core drill bits for metal
Bimetallic core drill bits for metal are made of high-quality high-speed steel alloyed with 8% cobalt

The diameter of these saw nozzles can be very different, but most often in a similar way to make tools of medium and large sizes (from 20 to 152 mm). Prices for these products vary depending on size and manufacturer.

A 20 mm nozzle will cost 2.16-3.60$, a 35 mm metal crown will cost 5-7.19$, large-sized 127 mm options will cost 12.94-18.69$.

The main technical and operational characteristics of bimetallic core drill bit for metal

should include:

  • high quality material that allows you to drill metal of any hardness;
  • the presence of side openings for the removal of waste and cooling of the cutting edge;
  • the shape and feature of the location of the teeth, contributing to the implementation of accurate slices, without burrs;
  • minimal (almost imperceptible) vibration during operation;
  • the presence of a shank, which makes it possible to attach the nozzle to a power tool of various capacities.
Bimetallic core drill bits for metal - made of two types of metal
Bimetallic core drill bits – made of two types of metal

Useful advice! Bimetallic crowns are more often used to make holes in hard and thick metal. When choosing a nozzle, be sure to pay attention to its compliance with the power tool that you plan to use

Diamond core for metal for drilling stone, concrete, ceramics

The first diamond crowns had a steel case with natural stones inserted along the cutting surface. It was a very effective tool, but it cost a lot of money. Modern industry produces artificial diamonds, which are not inferior to natural ones in terms of performance, therefore they are actively used for drilling and cutting various materials.

Two types of diamonds are fixed on the tooth-shaped edge: cutting and bulk. The latter are directly cut. Cutting are located on the inner and upper parts of the end part, they serve to protect the teeth from wear.

Diamond core for metal are a fairly expensive tool. For example, a crown of 35 mm will cost 4.31$.

It is not worth working with metal like a nozzle, it is intended for hard stone: concrete, granite, marble, etc. If there are metal inserts in concrete or ceramics, then this version of the core saw will be a suitable tool. The crown will confidently pass through the crumbling layers and easily cut the metal elements encountered on the path, preserving the working surface.

Diamond core for metal
Diamond core for metal is designed for hard stone: concrete, granite, marble

Useful advice! Diamond spraying on crowns can be different. Therefore, when choosing a nozzle for drilling stone with metal inserts, it is necessary to correctly evaluate the thickness of the latter and choose an annular mill with a suitable cutting end

How to choose a drill for metal core drill bits

A very important point that ensures the normal operation of the annular cutter is the fit of the used power tool. Most often, drills are used as a rotary device. They have various specifications. Here you need to pay attention to the following indicators:

  1. The power of a drill depends on the diameter of the core drill bits: the larger it is, the more powerful the power tool is needed. For example, a drill with a power of 600 watts is suitable for a 25 mm metal core drill bits.
  2. The ability to adjust the speed. The drill will be used not only for drilling, so it is extremely important to set the desired spindle speed. Crowns of small volume require a significant number of revolutions, for large dimensional indicators of the diameter, the rotation frequency must be reduced.
  3. Correspondence of the shape of the shank of the crown to the type of the cartridge. Cartridges can be of two types: key and key less. The first requires a special key, with which you can fix the nozzle (this option is considered more reliable.) The second is much simpler – you can fix the nozzle with one hand.
High power drills
High power drills are used to drill holes using metal core drill bits.

A 22 mm metal core does not require a change in the spindle speed during operation. It is possible to increase the load on the cutting edge due to the passage of a harder layer of material. To work in such conditions (drilling layers of different densities), a drill with the function of maintaining the frequency under load (constant electronics) can be a convenient option. The power tool will adjust the speed according to specific conditions.

Financial Benefits and Empowerment: Metal Core Drill Bits Sets

If the question arose of choosing a metal core drill bits for making holes in the metal, it means that a lot in the house is done with your own hands. What should we stop at: purchase a nozzle for a specific single purpose or buy a kit, looking into the future and warning of the need? In the case of an uncharacteristic isolated case, it is worthwhile to dwell on a separate product. And it will be useful to weigh and calculate what quality it is worth paying attention to.

Even for a layman seeking to have a certain arsenal of home tools, it is better to prefer a set of metal crowns for a drill. Benefits of purchasing this kit:

  • the ability to make holes of different diameters, changing only the annular cutting part;
  • no need to spend time searching for milling cutters of various diameters;
  • cost savings: a set of crowns is much cheaper than separately purchased nozzles;
  • Rigid plastic cases, in which the elements of the sets are laid, provide convenient and reliable storage of the tool.
set of metal core drill bits
A set of metal core costs significantly less than separately purchased nozzles

If you try to evaluate the financial benefits of acquiring a set, the calculation will be approximately as follows:

the price of an Enkor 40 mm metal core is 3.88$, a set of 5 similar milling cutters from this manufacturer has a cost of 10.93$. The price of one nozzle (on average) is almost half that.

Sets of metal core drill bits can consist of 5, 8, 10, 12, 13 units.

Useful advice! When buying a set of crowns for metal, you must pay attention to the presence of a centering drill in the kit. Its absence will not allow you to install the nozzle on the surface of the material exactly in the center.

Universal mobile installation: magnet drilling machine

Drilling machine on a magnet refers to those devices that, with simplicity of design, have great efficiency and profitability. Compared with a stationary drilling installation, it has several advantages:

  • has no restrictions on the placement of holes;
  • lightweight, mobile;
  • inexpensive.
Magnetic drilling machines
Magnetic drilling machines are designed for drilling, milling and threading in metal workpieces

On a stationary machine it is only possible to make holes of small sizes, since the distance between the crown and the working surface makes it impossible to place large workpieces. The magnetic device can be fixed on any metal plane by means of a special sole.

Such machines have various functional purposes. Using a 32 mm metal crown (and nozzles of smaller diameters), a hole can be made in a non-thick material. Reinforced circular cutters from 50 to 150 mm are used for thicker metal material.

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The magnetic part of the machines is quite powerful, it reaches 26 kN. This allows you to install the tool not only horizontally, but also at an angle, even vertically. If the surface is not smooth enough, the magnetic field does not reach the required value, additional clamps are used to fix the machine.

Magnetic drilling machines are more often used to make holes in large-sized structures, therefore, metal crowns of 50 mm or more are the most common nozzles for such devices.

machines are equipped with electric and pneumatic drives
The machines are equipped with electric and pneumatic drives

Proven reliable tool: metal core drill bits Bosch

One of the most popular are metal core drill bits Bosch. Most of the products manufactured by this company are bimetallic, that is, made of two types of metal: the body is made of high-speed steel, and the teeth are soldered and have a slightly different composition, which includes cobalt.

The diameter of the nozzles is very different, but the pitch is one inch: the minimum size is 9/16, that is, 14 mm, the maximum is 6, which corresponds to 152 mm. Some sizes in the line of Bosch crowns may not be found.

Landing for Bosch models is standard – it’s 1/2 or 5/8 inches, so that the crowns are combined with many types of power tools. As an adapter, the Power Change adapter is used. Replacing the annular cutter is simple and short, for this you should take the outer cage – the adapter will push the crown out.

It is very important to maintain the required number of revolutions. A 29 mm nozzle requires a frequency of 400 rpm, and a 40 mm metal crown requires 200. These requirements significantly extend the life of the nozzles.

metal core drill bits Bosch are made bimetallic
Bosch metal core drill bits are made bimetallic, that is, made of two types of metal

As for the price of Bosch ring mills for metal, it should be attributed to a moderate level.

A crown of medium diameter (38 mm) will cost about 11.50$. Although the cost of individual products may exceed this indicator. This company offers sets of hole saws. A set of 11 bimetallic products costs an average of 115.04$.

Metal core drill bits Bosch are made bimetallic “Zubr”: application features, prices

Core drill bits for metal “Zubr” – products of domestic production. Although it should be noted that a significant part of them are made in China. Analyzing reviews in social networks, we can conclude that approximately 30% of users have complaints about the quality of nozzles. Nevertheless, the majority assesses the tool as reliable and fully justifying the operational capabilities declared by the consumer.

Core are mainly bimetallic, with a wavy arrangement of teeth. The depth of the nozzles is standard – up to 40 mm. The size range of diameters is 14-152 mm. Core of this manufacturer have side holes for chip discharge, which makes the drilling process more comfortable. The holes after the Zubr cores are neat, with a smooth inner surface and even outer edges.

holes after the Zubr crowns
The holes after the Zubr cores are neat, with a smooth inner surface

Important! The resource of these crowns largely depends on the method of operation. From the application experience (information taken from user reviews), it follows that “Zubr” ring milling cutters should not cut metal with a thickness of more than 2 mm, or it is necessary to use additional water cooling.

High-quality Chinese version: core drill bits for metal Fit

Fit crowns are made in China. During production, Canadian technology is used. In the Russian market, the company has many large branches. Like many other manufacturers of similar products, the main part of metal core drill bits is bimetallic products.

Fit circular milling cutters can be attributed to the middle price segment, which makes them quite popular.

Small and medium sized nozzles have a triangular shank, each model is equipped with a center drill. A distinctive feature of crowns of this manufacturer can be considered the absence of an external protective coating. This should in no way be regarded as a flaw. Chrome-vanadium case does not need such an addition. The absence of traces of damage to the coating, although it does not affect the result of the tool, but helps to maintain the aesthetics of the product. As a result, the core operation becomes more comfortable.

FIT metal ring bit
FIT metal ring bit is  used for drilling holes in stainless steel

It should be noted that a metal thickness of 2 mm is not the limit for these nozzles. For example, with a 60 mm metal crown Fit, it is possible to drill a 3 mm sheet without harm to the cutting edge and without additional cooling. The shank of the nozzles over 32 mm is hexagonal, which allows you to firmly fix the cutter body on the power tool.

Metal core drill bits “Enkor”: sets and individual nozzles

Enkor is a domestic trading and manufacturing company that has tens of thousands of items of various products, including metal core drill bits. It is worth noting that among the nozzles offered by this manufacturer there are both bimetallic models and simpler ones made of carbide material.

This choice allows customers to find the right option in accordance with financial capabilities. A 22 mm metal carbide core will cost a little more than 1,5$.

Dimensional indicators of Enkor nozzles can be classified as standard: depth – up to 40 mm, diameter – from 14 to 152 mm. Core can go both complete with a holder and a center drill, and separately – the main body with a cutting edge. The latter option is convenient for those who already have ring cutters of other sizes. The product is also acceptable for those cases where there is a need to replace the crown due to significant wear on the cutting edge.

bimetallic models and in carbide material
Encore nozzles are manufactured both in bimetallic models and in carbide material

Useful advice! For more comfortable use, it is worthwhile to buy “Encore” crowns with an ejection spring, which does not allow the drilled fragment to get stuck in the nozzle body.

An affordable option is also the sets of crowns of this manufacturer.

For example, a set of 9 nozzles can be purchased for just 46.73$. The minimum diameter of the crowns is 19 mm, the maximum is 64 mm.

The kit includes a key, two adapters and a center drill. The small size of the transport case makes it convenient to store the tool.

Metal core drill bits: tips for proper use

Almost the entire new tool has an attractive appearance. On the pages of online stores you can find a meaningful description of the product, sometimes even supported by positive customer reviews. In order not to be disappointed with the acquisition, you need to seriously approach the study of the capabilities of the tool. You can evaluate drill bits for metal in this sequence.

  1. You need to make the right choice, for this it is worth carefully reading the labeling information. On the packaging must be indicated dimensional indicators, the country of origin (which to a certain extent speaks about the quality of the goods), the material of manufacture, especially accessories and devices. If the marking does not provide complete information about the ring mill, there is reason to doubt the quality of the tool.
  2. During use, the recommendations of the manufacturers should not be neglected. Improper use of the crown will damage the tool.
  3. If the centering drill is missing in the kit, you need to purchase it taking into account certain requirements. For example, a drill bit for a drill must have cross sharpening, otherwise instant and accurate centering will fail.
  4. The need to control the speed in the article has been said more than once. It should be emphasized that this condition is perhaps the most important for increasing the resource of crowns for metal.

With the correct selection and use of cores, a hole in the metal can be made in seconds. The tool is applicable for various domestic and industrial purposes. Compliance with technical requirements can extend the life of the device for a long time. Conversely, one ill-considered use can provoke defects that will make the metal core drill bits unsuitable for use.


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