The ring cutting method is used in cases where it is necessary to obtain a hole of a certain size in some material. A ring attachment that fits onto a drill, or a wood bit, is a device used by craftsmen for drilling in wood.
What is a wood crown?
A spray-coated attachment for processing plywood, chipboard, plastic, metal - a well-known device called a crown for drilling wood and other materials. It looks like a bowl with teeth located along the edge of the rim. It is put on a special drill chuck and rotates thanks to the power tool. The depth of the hole can vary, from a few millimeters to several centimeters. The number of teeth on it depends on the diameter of the cutter: the larger the wood crown, the greater the number of teeth on it. A typical set of ring nozzle is equipped with the following elements:
- head with cutting teeth;
- shank;
- central drill.
Why do you need a wood crown?
A ring attachment for a drill, with which you can easily drill a hole of any diameter, is widely used in repair work. A well-sharpened professional wood crown for socket boxes allows you to get neat recesses in walls, drywall, and wooden structures of the required size. A clean cut with a smooth inner surface without chips or burrs can be made using this attachment. There is no need to center the surface before drilling; sawing occurs quickly and quietly.
Is it possible to drill into metal with a wood crown?
A core drill does an excellent job of its main task - drilling holes. Experts confirm that it can be used to process not only wood. A crown for holes in wood, made of special grades of coated steel, is capable of processing more durable materials. With its help it is easy and simple to make a hole in non-ferrous metals of any hardness. When planning to work with complex materials, you should choose a drill with HCS markings; such a crown for hard wood and metal can easily cope with any task.
Tungsten carbide
The main part is abrasive tungsten carbide coating . The chips on the edge of the cutter are so strong that they cope with such stubborn materials as ceramic tiles .
The ideal type of nozzle if you need to make a recess for a socket box in a tiled wall . You can work with brick and stone. The only disadvantage of the products is that the service life is much lower than that of a diamond crown.
You cannot drill through reinforced areas , as the cutting edge will become jagged and unusable .
What is better: a wood crown or a ballerina?
Disputes continue in the furniture-making community about which tool to give preference to: a hole cutter or a ballerina jig. This wood core drill cuts a hole thanks to two sharply sharpened plates. By adjusting the distance between them, you can get a recess of any size. The main difference between the devices is that the crowns have a fixed size, and with the help of a ballerina you can drill a hole of any diameter. There is no definite answer which is better, it all depends on the specific type of work. When carving wood, a ballerina is best, and it is more convenient to drill holes in ceramics with a coated crown.
Preparatory operations for work
It must be taken into account that to prevent rotation, manufacturers create an irregularly shaped socket for fitting the tool. More experienced specialists remind you that for high-quality fixation it is necessary to tighten the thrust nut or bolt well. This will allow the cutting tool to be securely held in the grooves and not to become loose, deforming and bending the hole.
Example of the resulting hole
It is necessary to install the tool into the drill chuck only after all threads have been tightened. Then you can start drilling at the selected point. The process is practically no different from working with a classic drill. It is important during the operation to maintain maximum perpendicularity to the axis of rotation of the plane being treated. This factor is maintained in the first millimeters, then everything goes along the initially formed cylinder.
The number of revolutions for rotating the crown is also set in advance. It is worth considering that an increase in the diameter of a tool is combined with an increase in its vibration. This forces the use of more powerful drills if you take wood drills for large holes and large diameters. If possible, attach an additional handle to support and maintain perpendicularity.
When setting the rotation speed on a drill, you need to follow these rules:
- soft wood can be processed at speeds from 1000 (diameter 3.0-5.0 cm) to 2400 rpm (diameter 10-55 mm);
- for hard wood, it is advisable to increase the speed to 250 rpm (3.0-5.0 cm) to 600 rpm (1.0-1.5 cm);
- When using bits with carbide tips, you cannot lower the speed below 400-500 rpm, as the cutting edge will crumble.
VIDEO: How to drill a large diameter hole
How to choose a crown for wood?
Crowns designed for working with wood are easy to distinguish from others. They are painted black and made from metal alloys. A set of wood crowns looks like a device consisting of several cutting blades that can be replaced. Unlike a fixed cutter, such a tool does not always produce a high-quality cut. The harder the surface that needs to be drilled, the lower the drill speed should be. A wood inlaid crown differs in performance, which depends on several parameters:
- cutter material;
- tooth sharpening forms;
- number of teeth.
Wood crown sizes
The standard size of the socket box is 6.8 cm. Any set of ring cutters has a suitable attachment. In addition to this, many craftsmen use large-diameter wood crowns to drill a variety of technological and decorative holes. The size of the shank depends on the size of the device itself; for holes less than 65 mm in diameter it is recommended to use a shank of about 19 mm, for large recesses - from 3 cm. The following sizes of crowns are considered the most popular:
- 20 mm;
- 65 mm;
- 100 mm;
- 110 mm;
- 120 mm;
- 127 mm;
- 130 mm;
- 150 mm.
Distinctive features
Regardless of what material the crown purchased from Leroy Merlin will be used for, it has a standard design like all the others. It consists of the following elements:
- cutting head;
- elongated cylindrical or ribbed shank;
- guide drill.
The kit can be supplemented with a hexagon for high-quality clamping of a core drill.
Manufacturers offer two design options for wood crowns for deep drilling:
- non-separable solid metal structure for making a hole of the same size, for example, wood diameter 120 mm
Structure of a non-separable drill
- a collapsible design, which consists of a holder with a shank, to which a cutting ring of the required diameter is attached; for all mounted crowns there is a table in the instructions for use.
A stacked hole saw consists of several removable links of different diameters
In the first option, a solid ring is used, and in the second, an open ring in the form of a split cylinder is used. Quick ring changes speed up any machining process. Each cutting element has special technological holes for removing chips. They are made in the form of circles or slots on the side surfaces of the cylinders for small diameter tools and additionally at the ends for large ones.
Some craftsmen independently make a wood crown in their workshops, using a thick-walled metal pipe of the selected diameter.
Wood crowns - ranking of the best
Ready-made sets of ring drills are reliable and safe. The TOP of the best models of adjustable crowns for wood is as follows.
- The drilling set “Bison 29554-H15_z01”
consists of 15 items, the diameter of the bits varies from 1.9 to 12.7 mm. The centering drill is made of durable HSS steel. The set copes with different types of materials - wood, plastic, chipboard, plasterboard. - “MATRIX 70472”
– bimetallic wood crowns made of carbon steel, in a convenient case for storage and carrying. The set is completed with two holders and a centering drill, the maximum diameter of the bit is 2.8 mm. - “Bosch 2609255634”
- the model is compatible with any type of drill. The diameter of the holes that can be drilled using drills is from 46 to 81 mm. The wood bit provides a drilling depth of up to 3.1 cm, the weight of the set is only 500 g.
Pivot table
We looked at 4 types of crowns. It's time to sum it up. We present a summary table that shows the areas of application of cutters.
| № | Crown type | Concrete | Reinforced concrete | Ceramic tile | Drywall | Tree |
| 1 | Carbide | + | — | — | — | — |
| 2 | Diamond | + | + | + | — | — |
| 3 | Tungsten carbide | + | — | + | — | — |
| 4 | Bimetallic | — | — | — | + | + |
Standard crowns for socket boxes for concrete, plasterboard and wood differ in their characteristics. There is no universal option. But, using our recommendations, you can choose equipment with a decent ratio of cost and quality .
Good domestic crowns are the brands “ Zubr ” and “ Praktika ”. If you need something more reliable, you can purchase Messer , Bosh or Master Stayer .
DIY wood crown
Any craftsman may encounter a situation where a drill of a suitable diameter is not at hand. For work that does not require high precision and accuracy, you can make a wood crown for a rosette yourself in a couple of hours. The list of materials is minimal: a metal pipe of the required diameter, a “fist” from a door hinge, a drill, a screw, a rectangular steel plate.
- In the “fist”, using a vice, you need to drill a hole corresponding to the diameter of the drill.
- On the side of the “fist”, at a distance of at least 1 cm from the edge, another threaded hole should be made, intended for a fixing screw.
- Using a grinder, you need to make cuts along the edge of the pipe that imitate teeth.
- Weld a plate on the back of the pipe, in the center of which make a hole for the drill.
- To assemble the structure, a drill is inserted into the “fist” and secured with a screw. The lower part of the drill is placed in the crown, and the upper part is placed in the tool chuck (drill or screwdriver).
Carbide
The cutting part of carbide bits is brazed from an alloy called “win” ( 90 % tungsten and 10 % cobalt). The main advantage is low cost, and the main disadvantage is the short service life. Such cutters are very vulnerable and must be treated with care.
This is the right choice if you need to make 1 - 10 holes for socket boxes in concrete or brick walls. The products are not suitable for large volumes.
When it comes into contact with reinforcement, strong teeth are broken out of the “blank”, especially in products made in Asia. Therefore, you should avoid reinforced areas .
How to use wood crowns?
A core drill has the shape of a cylinder, one edge of which is made in the form of sharp teeth, and the other has a tip. A wood bit for a drill is essentially an attachment that can complement any hand tool. The cutter must be installed in a special glass and secured with a nut. The drill, which is located in the very center of the crown, is designed to determine the exact location of the center of the hole and obtain a perfect cut. If you follow the operating rules, any tools, including core drills, will last a long time.
How to sharpen a wood crown?
With active use, drills can become worn down and require sharpening. You can restore the sharpness of a wood drill bit yourself, but this will require certain skills. Maintaining the sharpening angle is an important point, without which it will not be possible to properly restore the functionality of the drill. Core drills for wood are made of soft metals, and they can be restored using hand tools and tools, for this the following are used:
- Grinder with a special grinding disc.
- Hand drill with sandpaper disc.
- Sharpener or emery machine.
