How And What To Drill

2023 Author: Douglas Hoggarth | [email protected]. Last modified: 2023-05-24 11:23

What, why and why we drill

Sometimes a seemingly simple task confuses us. Let's say that all you need is to drill a hole in the wall. Hang a shelf there, or attach a hook useful in the household. But no, the nasty hole is not made in any way as it should - it does not come out smoothly and neatly, your favorite kitchen cabinet hangs crookedly. Grandfather's hammer and a nail will not save the situation - a nail cannot cope with concrete. You cannot do without special tools in this process. We have conducted "field trials" and we authoritatively declare that drilling a beautiful hole is not an easy task at all. And it's not even the drilling process itself, although some skills are desirable here, but the choice of a suitable drill and its sharpening. I will not try to describe all the subtleties here - you cannot grasp the immensity, but I will tell you about the most important points.

Never forget the basic rule: the structure of the cutting tool must be harder than the material to be cut. This is understandable. Imagine that to drill a concrete wall, you use a drill that takes material no harder than plastic. I can say one thing: you had a good drill … Now throw in the trash what is left of it, and immediately stop mocking the drill. Because in this case, nothing good will come of your venture: the drill must be chosen for each specific case.

For drilling wood, chipboard, soft and hard plastics and metals, an ordinary drill made of high-strength steel is suitable (roughly speaking, a simple "piece of iron" without any "bells and whistles"). For stone, brick or concrete, use a carbide drill. These drills have plates of hard (harder than concrete and stone) alloys soldered on the tip. As such, it is usually used to win - hence the name "victor drills".

Typical drill for drilling in soft materials such as wood, steel, plastics, etc.

Справочка для тех, кто интересуется: победит по своей сути – это сплав вольфрама и кобальта в соотношении 90% к 10% соответственно. Разработан в 1929 году в СССР в основном для режущего инструмента. Сегодня уже используются другие вольфрам-кобальтовые сплавы (их модернизировали, удешевляли, делали более прочными, упрощали технологию изготовления – всего не перечислить, так что в результате получилось несколько десятков разновидностей), но все они «по привычке» носят название «победит». Кстати, нелишне упомянуть, что победитовые сверла материал не режут, а крошат, поэтому для сверления стены подходят идеально, но для работы по дереву, пластику или стали не годятся. Такие сверла не режут дерево, а рвут его волокна – отверстие получается «лохматым», некрасивым и имеет больший диаметр, чем надо. Примерно та же история со сверлением пластика, но, плюс ко всему вышесказанному, конструкция победитового наконечника в должной степени не обеспечивает отвод стружки, отверстие забивается, что приводит к уменьшению эффективности сверления и увеличению нагрузки на дрель. Сталь сверлить таким сверлом невозможно в принципе: отверстие просто не получится.

This is how it was until recently: you need to drill a piece of wood - take an ordinary drill, you need to make a hole in a brick wall - use a victorious one. But from the moment when information from “smart” books “for the elite” went “to the people”, the truth was revealed to a wide circle of simple folk craftsmen. It turns out that there are different brands to win. It also targets different materials. For harder materials (such as granite), use drills with hard to medium hard plates, while for softer materials (brick, soft concrete, etc.), you can use drills with soft to medium soft plates.

Now a little about sharpening methods. As I said, winder drills are sold ready-to-use - no sharpening is required. Therefore, we will talk about ways to sharpen ordinary drills.

If you look at the tip of the drill, it looks like it consists of two "shoulders". So, first of all, these "shoulders" must be exactly the same! No, there is absolutely no need to use high-precision measuring instruments - it is enough to estimate by eye. Why is this uniformity necessary? I will try to explain.

The place where these "shoulders" come together (like the top of a pyramid) will be the center of your future hole. In this case, the length of the larger of the "shoulders" will determine the radius of this hole. If the "shoulders" are the same, then the axis of rotation of the drill will coincide with the center of the hole. If not, then the diameter will be larger than the required one exactly by the amount of difference between the axis of the drill and the center of the "gnarled hole" that you get. In this case, the pros say that the drill has "smashed" the hole. Do not forget about the additional stress on the drill and your hands, not to mention the fact that the drill may break.

If you are drilling steel, hard plastic, etc., the alpha angle should be in the order of 25-30 °. When drilling soft plastic, wood and other soft materials, the angle can be increased up to 45-50 °. Moreover, when sharpening, it should be borne in mind that the drill must cut the material, therefore the back of the cutting edges should not touch the surface to be processed - otherwise, due to friction, the drill will overheat and fail.

In cases where the victorious drill is blunt, it can also be sharpened in the same way as an ordinary one. Moreover, the harder the material, the smaller the "alpha" angle. But keep in mind: victorious drills are afraid of overheating, carbide inserts crack and fall off when sharpening. This can be avoided. It is necessary to avoid strong heating of the drill tip on the sharpening stone and often cool the drill with a coolant (plain water is also suitable). But if the tip is still red-hot, then in no case should it be dipped in liquid - the plate will instantly crack. The drill should cool down "on its own", without your participation.

The way in which you need to initially sharpen the drills also depends on the hardness of the material being processed. For example, each drill is sharpened in such a way that it is impossible to do the same at home. As I already said, different grades of Pobedit differ only in the chemical formula and technology for obtaining the alloy. But such differences and details cannot be determined by eye. Therefore, the name of the material for which the drill is intended is almost always written on the packaging. If such information is not available, then these drills are most likely simply "grabbed" from some factory. And in this dubious case, their true purpose (and how and when they become blunt) you can only establish in the process. Another difference is the price. "Unnamed" drills are usually cheaper than "branded" ones.

Now let's figure out what and how much does our trade offer us?

Buying a drill is not a problem. Drills for various purposes and from different manufacturers are widely represented on sale: simple and victorious, in sets and by the piece. Sets can be from drills of "whole" denomination (for example: 2, 4, 6, 7 mm); with an interval of 0.5 mm (2; 2.5; 3; 3.5, etc.); for drilling under the thread; consisting of small diameter drills (up to 8 mm) and large (over 14 mm), etc. A box is given to the set - a useful thing for storage, and the drills will not be lost in the bowels of the apartment, which is very convenient.

True, small-diameter drills often break even from professionals, so you still have to buy them later. Personally, if I do something with small (up to 5 mm) drills, then I have at least a dozen of them in stock - so that later I do not run to the store during the work (it is troublesome, and the inspiration goes away). So I advise you not to be greedy and buy more at once.

I also want to talk in more detail about the sets for drilling under the thread. The technology is as follows. For example, I need to fasten together two absolutely smooth metal plates. To do this, in one of them I drill a through hole - the screw will enter there. In another plate, I need to make a counterpart - what I will screw this screw into. To do this, I again drill a hole (not necessarily through), and then using a special tool called a tap, I cut the thread. So, if the screw has a thread, for example, 5 mm, then the diameter of the hole for the counterpart must necessarily be less than this nominal (in this case, the hole diameter is 4.2 mm). See the table for full details.

Prices are very different - from 50-60 rubles per set to tens of dollars per drill. The cheapest sets are from unknown manufacturers with hieroglyphs on the packaging. I warn you, such unfortunate drills are a "headache" for a drill. They, like their compatriots - hacksaw files, are easily split, are very afraid of overheating - when sharpened, they instantly glow red-hot. But the most unpleasant thing is that they, as a rule, do not correspond to the face value written on them. I once had to work with a drill, which at a nominal 8 mm actually had a diameter of 8.6 mm. The rest of the drills in this set also “screwed up” by 0.1–0.2 mm. I advise you not to mess - your own dear!

Domestic specimens are quite good, and they are inexpensive - about 65–70 rubles for a set of ten drills. The only nuisance is that they probably should not be presented, for example, to your beloved father-in-law (and even more so to your mother-in-law) on your golden wedding anniversary - it’s very nondescript, I would say, just ugly packaging for them is offered by our manufacturers. And so there are practically no complaints about our drills. For use in a personal household - I highly recommend it, you will not regret it.

The imported kits on our market are mainly Polish, German and American. They are sold in beautiful packages and are more expensive than domestic ones, but, in my opinion, this price difference is in no way justified - they are no better than ours. This is just the case when there is absolutely no need to overpay. True, it is precisely because of the beautiful box that these drills are well suited as a holiday gift to the fastidious chef (father-in-law, brother, matchmaker) - he will appreciate it.

Winning drills of "cool" professional series are very expensive - not everyone can afford, but they are a pleasure to work with. Yes, and the drill itself shows - "super". The soldering of the carbide plates is neat, precise, the junction is practically invisible. The tip is so sharpened that, I repeat, it is impossible to repeat this at home. In addition, they have a declared service life during which the drills should not become blunt. (At the end of this period, the drill loses its uniqueness and, after sharpening, can be used as an ordinary "non-specialized" victorious drill.)

Well, now I'll tell you about several interesting series of winning drills that I tried in practice.

Collection "Extreme" SDS-Plus from "DeVolt"

The drills are produced with a diameter of 4, 5, 6, 8, 10, 12, 14 mm. The shank of the drill is round, and for drills with a diameter of 12, 14, 16 mm - hex (for better fixing in the chuck). Price - from 26 to 130 rubles.

The serrated cutting edge design allows for fast and efficient drilling in concrete, even if the drill hits a rebar. The cutting edge is not afraid of high temperatures (they arise just in contact with the reinforcement). The improved groove design (shaped like a jug extended upwards) effectively removes dust. Tungsten carbide inserts are fastened with a solder that is more resistant to overheating (using a special technology and with the addition of copper) than conventional victory drills. The hole is almost chipped free at the edges.

Collection for stone work from "Bosch"

Blue Granite series for granite and other hard stones

Drill diameter from 3 to 20 mm. Price from 4 to 17 German marks (from 52 to 221 rubles) for one drill. The drills are designed for impact drills, are extremely bending strength, and are more resistant when drilling in concrete than simple victory drills. Precisely ground carbide insert; Helix shape with deep U-shaped flute significantly reduces chip clogging.

And here is the paradox! The drill really famously cracked down on the imported granite facing slab, but for some reason it stumbled when drilling our ordinary domestic brick. No, I, of course, still "won" and drilled the brick. But at the same time the drill howled so hysterically that even crying, I felt sorry for her, my dear.

The Silver Percussion series are impact drills designed specifically for masonry and the toughest concrete.

Diameter from 3 to 20 mm. Price from 2.5 to 60 German marks (from 32.5 to 780 rubles) for one drill. High bending strength, fast removal of drill chips. I don’t know what kind of concrete the wall I was practicing was made of, but the drill coped with it easily. By the way, my favorite brick was drilled faster than I could say: "Wow!" This has a certain disadvantage: it is difficult to control the final diameter of the hole - the drill instantly "breaks" it.

The Impact series is ideal for processing natural and artificial stones, brickwork.

Diameter from 3 to 25 mm. Price from 3 to 55 German marks (from 39 to 715 rubles) for one drill. I had no stones at my disposal - neither natural nor any other, so I tried the drill again on a long-suffering brick. It turned out not bad, but the previous one “liked” my drill more: she practically “did not notice” the drilling process.

Drills of the Karat series are universal, suitable for almost any material (except for concrete and artificial stone - here the use of these drills is undesirable: blunt the drill and overload the drill).

Diameter from 3 to 14 mm. Price from 5.5 to 25 German marks (from 71.5 to 325 rubles) for one drill. Beautiful, neat holes are produced by sharpened cutting edges and centering sharpening. In principle, not bad (for universal) drills, but I am having some problems. When my drill was struggling with granite, judging by the heart-rending howl, she was very unhappy and experienced great overload. And when drilling an ordinary brick wall, the drill periodically clogged with crumbs and went as if in jerks.

What I really liked was that the hole in the tile really turned out to be perfectly clean, without chips. True, this hole turned out only the third time - apparently, here you also need to be able to.

The "Black Quartz" series drills are excellent for cutting roof tiles, ceramics or tiles.

Diameter from 3 to 14 mm. Price from 3.5 to 13 German marks (from 45.5 to 169 rubles) per drill. Withstand heavy loads and make extremely precise and "correct" holes - clean, chipping-free. I can't add anything on my own, except that all of the above is true. I checked it myself - the drill "gnaws" well on ceramics and tiles (I didn't have any tiles). By the way, there are chips at the edges, but very small, they are practically invisible.

So, in general, my opinion is this: working with "highly specialized" drills is much more convenient. However, buying a “separate” set of drills for each specific material is quite expensive. So it all depends on how often you drill the walls: if once a year, then this series is the best option for you.

In addition to those listed and personally tested by me, there are other interesting collections of drills in our stores. But I didn’t work with them, so I don’t know any details. But in the future I will definitely try and tell you, dear readers.

In the following, we will definitely talk about what else you can do with a drill using various attachments. For example, I will show you how to use a diamond bit to cut a hole in a pipe. Or how to prepare a wall for painting with a drill. Or what and how else can you make a drill (and its companions-attachments) necessary and useful in the household. Until then, good luck!

Alexander Rubin