You can easily drill a wall or prepare a through hole by choosing the right drill for the equipment used, be it a drill or a hammer drill. For any purpose, the hole must be straight-edged and of the correct size. Accuracy is easy enough. Let’s talk about the right choice of drills and the features of wall drilling.
You need to select the type of shank (hex, cylinder or SDS mount) suitable for the selected tool and the working part, based on the wall material.
In the store, the color of the drills and drills will definitely catch your eye:
- Faded gray color – drills for metal or wood with additional hardening. Reference strength and durability.
- Black metallic color – at the last stage of production, the drill was treated with superheated steam to form an oxide protective film. Increased durability, but strength depends on the choice of steel grade.
- Bright golden uniform color of the entire drill – the result of applying the stress relief technique inside the drill material.
- A yellowish tint (golden) mainly only in the working part of the drill – a protective coating based on titanium compounds, which increases the strength of the cutting edge and the entire working part.
Concrete, brick, stone
You will need a drill with a carbide insert. The plate is welded at the end of the working area of the drill, made of an alloy of cobalt, tungsten carbide and a number of other elements, which together give it strength and resistance to abrasion. The name of the alloy is “win”, firmly entrenched in everyday life and in the technical environment.
When choosing a winning drill in a store, you should pay attention to how smoothly the nozzle is welded. Often there are drills of nameless manufacturers with poor centering, which is easy to determine even by eye.
The process of drilling holes in concrete or stone is based on the crushing process, so a hammer drill is used as the main tool. An impact drill is suitable for bricks. The type of drill shank is determined depending on the selected tool.
For a hammer drill:
- SDS, SDS-plus – fastening with a diameter of 10 mm and a 40 mm part inserted into the chuck for quick change of the drill used in rotary hammers. Drill diameter 4–26 mm, length from 110 to 1000 mm.
- SDS-max is a mount for large drills used with heavy-duty rock drills. Shank diameter 18 mm, suitable for concrete drills over 20 mm in diameter.
For impact drills – cylindrical shank. Drill diameter – 4-11 mm, length – up to 110 mm.
For drilling holes with a diameter of 4-10 mm and a depth of up to 100 mm for a dowel or anchor, drill bits with SDS-plus fastening or drills with a cylindrical shank are suitable.
For holes with a diameter of up to 42 mm and a depth of up to a meter or through holes for laying communications, pipes or connecting an air conditioner, drill bits with SDS-plus, SDS-max shank are used.
When drilling deep holes with a diameter of more than 10 mm, it is advisable to perform the work in two or three passes, selecting drills from a smaller diameter to a larger one, the same applies to the length of the drill. First, short drills of 110 mm are used, and then already half-meter or one meter, in order to reduce the risk of damage to the larger drill and ensure an even edge at the hole.
To drill holes in the wall with a diameter of over 42 mm, crowns are used, for example, to install a socket outlet. It is a cutting tool with an annular cutting edge, more often mounted on a cylindrical base with SDS-plus, SDS-max shank. The cutting edge is formed by a series of teeth in an alloy vanquished or diamond-coated.
For small holes of 4–25 mm, special cone drills with diamond dusting are used. The main task is to go through the tile surface and its base. After that, you need to switch to a drill suitable for the material of the wall, and continue drilling with it (wins, a drill for metal or wood).
It is especially difficult to start drilling in a fixed position. It is necessary to stick an adhesive tape over the mark or tap a dot along the mark, knocking down neatly part of the glaze or polished surface so that the drill does not “walk” along the surface.
Large-diameter holes for the outlet are drilled with a drill by a ballerina. There is a sputtered support cone on the main axis. An adjustable shoulder with a fixed cutting tip is retracted from it. It is better to start at low speeds until the surface of the tile is passed. When the surface has been passed by 2-3 mm, you need to go to the crown for the corresponding wall material.
Drills for metal have the most familiar appearance. This is a helical working part and a cylindrical shank. Tapered sharpening without a sharp tip with an angle of inclination of the cutting edges from 90 to 140 degrees. The spiral is formed by two protruding parts and twisted at an angle of 27 degrees. The outer edge has a cutting edge along its entire length, due to which, in soft metals and wood, you can widen the holes with lateral movements of the drill, like a milling cutter.
Depending on the specific metal, the angle of inclination of sharpening at the tip of the working part is selected:
- for most grades of steel used in construction – 140 degrees;
- duralumin, bronze and brass – 110-120 degrees;
- copper, aluminum wood and plastic – 90-100 degrees.
Universal drill sets contain drills for metal, mainly with an average sharpening angle of 110-120 degrees, which is quite enough for most tasks.
When drilling walls, drills for metal are needed if there are reinforcement or elements of a profile frame inside the base material. It is impossible to pass these obstacles with a drill with a victorious tip, both the tool and the already covered section of the hole will deteriorate. It is necessary to switch to a conventional drill with a drill for metal, go through the obstacle, and then continue to work with a drill or drill on the selected material.
A distinctive feature of drills for wood with a diameter of 2 to 16-24 mm from those for metal is the presence of a sharp tip in the center of the main sharpening at the end of the working part. This is necessary for the correct centering of the drill in relation to the hole and for an easy start. The tip easily enters the wood grain in a strictly marked place and no longer allows the drill to jump off.
Drills for metal are suitable for drilling wood, drywall, but often the holes turn out to be uneven, especially if you do not select the required drill speed depending on the type of wood. In soft rocks, the fibers at the edges of the hole will diverge, and in hard rocks, splitting is possible if the drill moves.
For large and / or deep holes, use:
- Pen (feather) drill.
- Twist drill.
- Saw bits for wood.
The nib drill is a flat insert with two sharpened edges and a point for determining the direction. Fixed point drills help to drill holes with a diameter of 8–45 (60) mm. However, without rigid fixation of the tool and the base, the shape of the hole is unlikely to be even, and due to the absence of side cutting edges, the walls of the holes are often obtained with broken fibers..
Ballerinas on wood help to drill large-diameter holes, but only in the base with a thickness not exceeding a certain threshold, for example, up to 50-70 mm.
The twist drills are optimized for extracting wood chips and are a direct analogue of large concrete drills. Used for drilling holes up to 45 mm in diameter and up to a meter deep.
The saw crowns ream the material around the circumference. A frequent file is formed along the edge of the crown. Then you need to use a chisel to select the material inside, if you need to make a blind hole.
For foam concrete of strong grades over M800, the same methods and tools are used as for concrete or brick. For lightweight foam concrete used for wall insulation below M600, it is sufficient to use methods and tools as for wood, only preference is given to cutting tools with a protective coating on a titanium base.