". Today I want to talk about how easy it is to make feather drills on wood.
The other day I needed to drill in Chipboard holes large diameter, namely 40 and 20 mm. And then it turned out that I do not have the necessary drills !!!
No... Of course I have a lot of different pen drills. Both ordinary and several adjustable ones. But, here, the trouble is that I was now working at home in the basement, and my drills are on the other side of the city, namely, at the construction site, where I used them for the last time ...
And so I decided to quickly make the necessary drills from what was at hand ...
And, in fact, I needed the following for this:
1. a piece of sheet "stainless steel", 2 mm thick. (Not necessarily "stainless steel" ... I just had it lying around ..)
2. Metal pin with a diameter of 10 mm. (It can also be thinner ... It's just that I had this one))))
3. Bolt (screw) M6 (or thinner).
(Before I start the story, I want to apologize for the poor quality of the photo. The fact is that I had no time to photograph the process step by step, so I just turned on the video recording on my smartphone, and then took screenshots from it ...)
So where did I start... Found a piece sheet metal, 2 mm thick. I came across such a piece of "stainless steel" under my arm
I started with a drill with a diameter of 40mm. First, I drew a drill blank on a piece of stainless steel:
Using a grinder with a cutting wheel, I cut out the workpiece:
After that, I made the core of the drill itself. I decided to make it from a ten-millimeter rod that I had lying around in my "scrap metal":
There was no thinner bar at hand ... But I thought that this one would do. After all, a rod of this diameter will fit into any cartridge of a household drill. Of course, its thickness regulates the minimum diameter of the drill, but I always have drills up to twelve millimeters in stock ... (These are drills for metal, but they can also be easily used for wood). And you only need feathers large diameters..
I cut off a piece of the rod desired length:
Clutching in a vise, I cut a diametrical slot with a cutting wheel. I estimated the depth of the cut by eye, simply by attaching the workpiece and noting such a depth, "so that it was normal" ...))))
After that, I checked if my "pen" is inserted into the slot of the rod:
Aligning exactly in the center, I made marks on the plane corresponding to the thickness of the rod with a marker:
Then I made cuts along these lines:
Having changed cutting wheel on the grinder, I chose the metal between the slots.
Now you need to fix the pen in the rod. It's easier, of course, to just "drip" welding. But, in order not to make a second rod (after all, in addition to forty-millimeter, I also needed twenty-millimeter), I decided to fix it with a screw. To do this, I drilled a hole in the rod, perpendicular to the slot. I used a drill with a diameter of 5 mm.
Then I drilled the upper half of the rod (to the slot) with a drill, six millimeters in diameter:
And in the lower half I cut the M6 thread:
After that, I inserted the pen into the rod, aligned it, and, marking the center with a drill, removed it and drilled a hole with a diameter of 6 mm.
Now you can insert the pen into the rod and fasten it with a screw:
I used an M6 bolt as a screw. It was easier for me to cut the thread. But if you don’t have taps on hand, you can use it as a bolt - screw the nut on the other side. It will not hurt, it will just not be so convenient to mount it - you will need two keys ...
Now let's sharpen our drill. I used homemade diamond cup sandpaper... Just because I had it on hand:
And you can sharpen anything, even with a grinder ... There is no need to observe a certain angle here. It should not be made too sharp simply:
All! The drill is ready. It is quite easy to drill through wood and chipboard:
Because the rod was already ready, it was not difficult to make a second pen, 20 millimeters wide:
Of course, such drills are not suitable for permanent, professional work... For this you need purchased drills made of good steel ... But I'm not a professional!!! I am a do-it-yourselfer! And the last time before this case I used a pen drill of this diameter about ten years ago !!! And here again it took !!)))).
It took me about twenty minutes to make. (During this time I didn’t go, I wouldn’t even go to the store for him))). And the production of subsequent diameters is half as much ...
And I did the job for them - I drilled the hole I needed. After that, I'll put it on the shelf, and next time I'll need it....maybe in a year...maybe in five!!! ... (Or maybe it won’t be needed at all!)))) But it will no longer need to be bought or made ...)))
By the way, at a construction site, when I needed to fasten beams and rafters, I also used just such a drill. At that moment, I lent my long wood drill to a friend, and, as it usually happens, he did not return it to me in time ... And, in order not to lose days, I lost minutes - I made the same drill, only half a meter long, and did the job ...
For such purposes, such drills are very well suited !!!
The work of drilling holes in metal, depending on the type of holes and the properties of the metal, can be performed different instrument and using various methods. We want to tell you about drilling methods, tools, as well as safety precautions when performing these works.
Drilling holes in metal may be needed during repairs engineering systems, household appliances, car, creating structures from sheet and profile steel, designing crafts from aluminum and copper, in the manufacture of circuit boards for radio equipment, and in many other cases. It is important to understand what kind of tool is needed for each type of work so that the holes are the right diameter and in a strictly intended place, and what safety measures will help to avoid injury.
Tools, fixtures, drills
The main tools for drilling are hand and electric drills and, if possible, drilling machines. The working body of these mechanisms - the drill - can have a different shape.
There are drills:
- spiral (most common);
- screw;
- crowns;
- conical;
- feathers, etc.
Drill production various designs standardized by numerous GOSTs. Drills up to Ø 2 mm are not marked, up to Ø 3 mm - the section and steel grade are indicated on the shank, larger diameters may contain additional information. To obtain a hole of a certain diameter, you need to take a drill a few tenths of a millimeter smaller. The better the drill is sharpened, the smaller the difference between these diameters.
Drills differ not only in diameter, but also in length - short, elongated and long are produced. important information is the ultimate hardness of the metal being processed. The shank of the drills can be cylindrical and conical, which should be borne in mind when selecting a drill chuck or adapter sleeve.
1. Drill with cylindrical shank. 2. Tapered shank drill. 3. Drill with a sword for carving. 4. Center drill. 5. Drill with two diameters. 6. Center drill. 7. Conical drill. 8. Conical multi-stage drill
For some work and materials, special sharpening is required. The harder the metal being processed, the sharper the edge must be sharpened. For thin sheet metal, a conventional twist drill may not be suitable, you will need a tool with a special sharpening. Detailed recommendations For various types drills and processed metals (thickness, hardness, hole type) are quite extensive, and in this article we will not consider them.
Various types of drill sharpening. 1. For hard steel. 2. For of stainless steel. 3. For copper and copper alloys. 4. For aluminum and aluminum alloys. 5. For cast iron. 6. Bakelite
1. Standard sharpening. 2. Free sharpening. 3. Diluted sharpening. 4. Heavy sharpening. 5. Separate sharpening
To fix parts before drilling, a vice, stops, conductors, corners, clamps with bolts and other devices are used. This is not only a safety requirement, it is actually more convenient, and the holes are of better quality.
To chamfer and process the surface of the channel, they use a countersink of a cylindrical or conical shape, and to mark a point for drilling and so that the drill does not “jump off” - a hammer and a center punch.
Advice! The best drills until now, they are considered to be issued in the USSR - exact adherence to GOST in geometry and metal composition. German Ruko with titanium coating are also good, as well as drills from Bosch - proven quality. Good feedback about Haisser products - powerful, usually with a large diameter. The Zubr drills, especially the Cobalt series, proved to be worthy.
Drilling modes
It is very important to correctly fix and guide the drill, as well as select the cutting mode.
When making holes in metal by drilling important factors are the number of revolutions of the drill and the feed force applied to the drill, directed along its axis, providing the penetration of the drill at one revolution (mm / rev). When working with different metals and drills, different cutting conditions are recommended, and the harder the metal being processed and the larger the diameter of the drill, the lower the recommended cutting speed. Index correct mode— beautiful, long shavings.
Use the tables to choose the right mode and not dull the drill prematurely.
| Feed S 0 , mm/rev | Drill diameter D, mm | |||||||||
| 2,5 | 4 | 6 | 8 | 10 | 12 | 146 | 20 | 25 | 32 | |
| Cutting speed v, m/min | ||||||||||
| When drilling steel | ||||||||||
| 0,06 | 17 | 22 | 26 | 30 | 33 | 42 | — | — | — | — |
| 0,10 | — | 17 | 20 | 23 | 26 | 28 | 32 | 38 | 40 | 44 |
| 0,15 | — | — | 18 | 20 | 22 | 24 | 27 | 30 | 33 | 35 |
| 0,20 | — | — | 15 | 17 | 18 | 20 | 23 | 25 | 27 | 30 |
| 0,30 | — | — | — | 14 | 16 | 17 | 19 | 21 | 23 | 25 |
| 0,40 | — | — | — | — | — | 14 | 16 | 18 | 19 | 21 |
| 0,60 | — | — | — | — | — | — | — | 14 | 15 | 11 |
| When drilling cast iron | ||||||||||
| 0,06 | 18 | 22 | 25 | 27 | 29 | 30 | 32 | 33 | 34 | 35 |
| 0,10 | — | 18 | 20 | 22 | 23 | 24 | 26 | 27 | 28 | 30 |
| 0,15 | — | 15 | 17 | 18 | 19 | 20 | 22 | 23 | 25 | 26 |
| 0,20 | — | — | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 |
| 0,30 | — | — | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 19 |
| 0,40 | — | — | — | — | 14 | 14 | 15 | 16 | 16 | 17 |
| 0,60 | — | — | — | — | — | — | 13 | 14 | 15 | 15 |
| 0,80 | — | — | — | — | — | — | — | — | — | 13 |
| When drilling aluminum alloys | ||||||||||
| 0,06 | 75 | — | — | — | — | — | — | — | — | — |
| 0,10 | 53 | 70 | 81 | 92 | 100 | — | — | — | — | — |
| 0,15 | 39 | 53 | 62 | 69 | 75 | 81 | 90 | — | — | — |
| 0,20 | — | 43 | 50 | 56 | 62 | 67 | 74 | 82 | - | - |
| 0,30 | — | — | 42 | 48 | 52 | 56 | 62 | 68 | 75 | — |
| 0,40 | — | — | — | 40 | 45 | 48 | 53 | 59 | 64 | 69 |
| 0,60 | — | — | — | — | 37 | 39 | 44 | 48 | 52 | 56 |
| 0,80 | — | — | — | — | — | — | 38 | 42 | 46 | 54 |
| 1,00 | — | — | — | — | — | — | — | — | — | 42 |
Table 2. Correction factors
Table 3. Revolutions and feeds for various drill diameters and drilling in carbon steel
Types of holes in metal and methods for drilling them
Types of holes:
- deaf;
- through;
- half (incomplete);
- deep;
- large diameter;
- for internal thread.
Threaded holes require the determination of diameters with tolerances established in GOST 16093-2004. For common hardware, the calculation is given in table 5.
Table 5. The ratio of metric and inch threads, as well as the selection of the hole size for drilling
| Metric thread | Inch thread | Pipe thread | |||||||
| Thread diameter | Thread pitch, mm | Thread hole diameter | Thread diameter | Thread pitch, mm | Thread hole diameter | Thread diameter | Thread hole diameter | ||
| min. | Max. | min. | Max. | ||||||
| M1 | 0,25 | 0,75 | 0,8 | 3/16 | 1,058 | 3,6 | 3,7 | 1/8 | 8,8 |
| M1.4 | 0,3 | 1,1 | 1,15 | 1/4 | 1,270 | 5,0 | 5,1 | 1/4 | 11,7 |
| M1.7 | 0,35 | 1,3 | 1,4 | 5/16 | 1,411 | 6,4 | 6,5 | 3/8 | 15,2 |
| M2 | 0,4 | 1,5 | 1,6 | 3/8 | 1,588 | 7,7 | 7,9 | 1/2 | 18,6 |
| M2.6 | 0,4 | 2,1 | 2,2 | 7/16 | 1,814 | 9,1 | 9,25 | 3/4 | 24,3 |
| M3 | 0,5 | 2,4 | 2,5 | 1/2 | 2,117 | 10,25 | 10,5 | 1 | 30,5 |
| M3.5 | 0,6 | 2,8 | 2,9 | 9/16 | 2,117 | 11,75 | 12,0 | — | — |
| M4 | 0,7 | 3,2 | 3,4 | 5/8 | 2,309 | 13,25 | 13,5 | 11/4 | 39,2 |
| M5 | 0,8 | 4,1 | 4,2 | 3/4 | 2,540 | 16,25 | 16,5 | 13/8 | 41,6 |
| M6 | 1,0 | 4,8 | 5,0 | 7/8 | 2,822 | 19,00 | 19,25 | 11/2 | 45,1 |
| M8 | 1,25 | 6,5 | 6,7 | 1 | 3,175 | 21,75 | 22,0 | — | — |
| M10 | 1,5 | 8,2 | 8,4 | 11/8 | 3,629 | 24,5 | 24,75 | — | — |
| M12 | 1,75 | 9,9 | 10,0 | 11/4 | 3,629 | 27,5 | 27,75 | — | — |
| M14 | 2,0 | 11,5 | 11,75 | 13/8 | 4,233 | 30,5 | 30,5 | — | — |
| M16 | 2,0 | 13,5 | 13,75 | — | — | — | — | — | — |
| M18 | 2,5 | 15,0 | 15,25 | 11/2 | 4,333 | 33,0 | 33,5 | — | — |
| M20 | 2,5 | 17,0 | 17,25 | 15/8 | 6,080 | 35,0 | 35,5 | — | — |
| M22 | 2,6 | 19,0 | 19,25 | 13/4 | 5,080 | 33,5 | 39,0 | — | — |
| M24 | 3,0 | 20,5 | 20,75 | 17/8 | 5,644 | 41,0 | 41,5 | — | — |
through holes
Through holes penetrate the workpiece completely, forming a passage in it. A feature of the process is the protection of the surface of the workbench or tabletop from the exit of the drill beyond the workpiece, which can damage the drill itself, as well as provide the workpiece with a “burr” - a hart. To avoid this, use the following methods:
- use a workbench with a hole;
- put a gasket made of wood or a “sandwich” under the part - wood + metal + wood;
- put a metal bar under the part with a hole for the free passage of the drill;
- reduce the feed rate at the last stage.
The latter method is mandatory when drilling holes "in place" so as not to damage closely spaced surfaces or parts.
Holes in thin sheet metal are cut with spatula drills, because the twist drill will damage the edges of the workpiece.
blind holes
Such holes are made to a certain depth and do not penetrate the workpiece through and through. There are two ways to measure depth:
- limiting the length of the drill with a sleeve stop;
- limiting the length of the drill with an adjustable stop chuck;
- using a ruler fixed on the machine;
- a combination of methods.
Some machines are equipped with an automatic feed to a given depth, after which the mechanism stops. During the drilling process, it may be necessary to stop the work several times to remove the chips.
Holes of complex shape
Holes located on the edge of the workpiece (half) can be made by connecting two workpieces or a workpiece and a gasket with faces and clamping with a vise and drilling a full hole. The gasket must be made of the same material as the workpiece being processed, otherwise the drill will “leave” in the direction of least resistance.
A through hole in the corner (shaped rolled metal) is performed by fixing the workpiece in a vice and using a wooden gasket.
It is more difficult to drill a cylindrical workpiece tangentially. The process is divided into two operations: preparation of a platform perpendicular to the hole (milling, countersinking) and drilling itself. Drilling holes in surfaces located at an angle also begins with the preparation of the site, after which a wooden gasket is inserted between the planes, forming a triangle, and a hole is drilled through the corner.
Hollow parts are drilled, filling the cavity with a cork made of wood.
Stepped holes are produced using two techniques:
- Reaming. The hole is drilled to the full depth with a drill of the smallest diameter, after which it is drilled to a given depth with drills with diameters from smaller to larger. The advantage of the method is a well-centered hole.
- Reducing the diameter. A hole of maximum diameter is drilled to a given depth, then the drills are changed with a successive decrease in diameter and a hole deepening. With this method, it is easier to control the depth of each step.
1. Drilling a hole. 2. Diameter reduction
Large diameter holes, annular drilling
Obtaining holes of large diameter in massive workpieces, up to 5-6 mm thick, is a laborious and costly business. Relatively small diameters - up to 30 mm (maximum 40 mm) can be obtained using cone, and preferably step-cone drills. For holes with a larger diameter (up to 100 mm), hollow bi-metal hole saws or hole saws with carbide teeth with a center drill will be required. Moreover, the craftsmen traditionally recommend Bosch in this case, especially on hard metal, such as steel.
Such annular drilling is less energy-intensive, but may be more financially costly. In addition to drills, the power of the drill and the ability to work at the lowest speeds are important. Moreover, the thicker the metal, the more you want to make a hole on the machine, and when in large numbers holes in a sheet with a thickness of more than 12 mm, it is better to immediately look for such an opportunity.
In a thin-sheet blank, a large-diameter hole is obtained using narrow-toothed crowns or a milling cutter mounted on a grinder, but the edges in the latter case leave much to be desired.
Deep holes, coolant
Sometimes a deep hole is required. In theory, this is a hole whose length is five times the diameter. In practice, deep drilling is called, requiring forced periodic removal of chips and the use of coolants (cutting fluids).
In drilling, coolants are needed primarily to reduce the temperature of the drill and workpiece, which are heated by friction. Therefore, when making holes in copper, which has a high thermal conductivity and is itself capable of removing heat, coolant can be omitted. Cast iron is drilled relatively easily and without lubrication (except for high-strength ones).
In production, industrial oils, synthetic emulsions, emulsols and some hydrocarbons are used as coolants. In home workshops you can use:
- technical vaseline, castor oil - for mild steels;
- laundry soap— for aluminum alloys of D16T type;
- a mixture of kerosene with castor oil - for duralumin;
- soapy water - for aluminum;
- turpentine diluted with alcohol - for silumin.
The universal coolant can be prepared independently. To do this, you need to dissolve 200 g of soap in a bucket of water, add 5 tablespoons of machine oil, you can use it, and boil the solution until a soapy homogeneous emulsion is obtained. Some masters use lard to reduce friction.
| Processed material | Coolant |
| Steel: | |
| carbonaceous | Emulsion. Sulfurized oil |
| structural | Sulfurized oil with kerosene |
| instrumental | Blended oils |
| alloyed | Blended oils |
| Ductile iron | 3-5% emulsion |
| Cast iron | Without cooling. 3-5% emulsion. Kerosene |
| Bronze | Without cooling. Blended oils |
| Zinc | Emulsion |
| Brass | Without cooling. 3-5% emulsion |
| Copper | Emulsion. Blended oils |
| Nickel | Emulsion |
| Aluminum and its alloys | Without cooling. Emulsion. Mixed oils. Kerosene |
| Stainless, high temperature alloys | Mixture of 50% sulfurated oil, 30% kerosene, 20% oleic acid (or 80% sulfofresol and 20% oleic acid) |
| Fiber, vinyl plastic, plexiglass and so on | 3-5% emulsion |
| Textolite, getinaks | Compressed air blowing |
Deep holes can be made by solid and annular drilling, and in the latter case, the central rod formed by the rotation of the crown is broken out not entirely, but in parts, weakening it with additional holes of small diameter.
Solid drilling is performed in a well-fixed workpiece with a twist drill, through the channels of which coolant is supplied. Periodically, without stopping the rotation of the drill, it is necessary to remove it and clean the cavity from chips. The work with a twist drill is carried out in stages: first, a short hole is taken and a hole is drilled, which is then deepened with a drill of the appropriate size. With a significant depth of the hole, it is advisable to use guide bushings.
With regular drilling deep holes it is possible to recommend the purchase of a special machine with automatic feeding Coolant to the drill and precise centering.
Drilling by marking, template and jig
You can drill holes according to the markings made or without it - using a template or a jig.
Marking is done with a punch. A hammer blow marks a place for the tip of the drill. A felt-tip pen can also mark a place, but a hole is also needed so that the tip does not move from the intended point. The work is carried out in two stages: preliminary drilling, hole control, final drilling. If the drill "left" from the intended center, notches (grooves) are made with a narrow chisel that guide the tip to a given place.
To determine the center of a cylindrical workpiece, a square piece of tin is used, bent at 90 ° so that the height of one shoulder is approximately one radius. Applying a corner from different sides of the workpiece, draw a pencil along the edge. As a result, you have an area around the center. You can find the center by the theorem - the intersection of perpendiculars from two chords.
A template is needed when making a series of parts of the same type with several holes. It is convenient to use it for a pack of thin-sheet blanks connected with a clamp. This way you can get several drilled blanks at the same time. Instead of a template, a drawing or diagram is sometimes used, for example, in the manufacture of parts for radio equipment.
The conductor is used when the accuracy of maintaining the distances between the holes and the strict perpendicularity of the channel are very important. When drilling deep holes or when working with thin-walled tubes, in addition to the conductor, guides can be used to fix the position of the drill relative to the metal surface.
When working with a power tool, it is important to remember human safety and prevent premature wear of the tool and possible marriage. In this regard, we have collected some useful tips:
- Before work, you need to check the fastening of all elements.
- Clothing when working on a machine or with an electric drill should not be with elements that can fall under the action of rotating parts. Protect your eyes from chips with goggles.
- The drill, when approaching the surface of the metal, must already rotate, otherwise it will quickly become dull.
- It is necessary to remove the drill from the hole without turning off the drill, reducing the speed if possible.
- If the drill does not go deep into the metal, then its hardness is lower than that of the workpiece. Increased hardness in steel can be detected by running a file over the sample - the absence of traces indicates increased hardness. In this case, the drill must be selected from a carbide with additives and work at low speeds with a small feed.
- If a small diameter drill does not fit well in the chuck, wind a few turns of brass wire around its shank, increasing the gripping diameter.
- If the surface of the workpiece is polished, put a felt washer on the drill to ensure that it does not scratch even when it comes into contact with the drill chuck. When fastening workpieces made of polished or chrome-plated steel, use spacers made of fabric or leather.
- When making deep holes, a rectangular piece of foam placed on a drill can serve as a measuring instrument and at the same time blow off small chips while rotating.
Drilling wood is one of the most common tasks in repair and construction, but it is not always possible to purchase a high-quality wood drill. Therefore, it is very important to know how to choose a good tool, and be able to sharpen a dull product!
Modern drills are often sold with a set of different drills, however, basically, it is always the same type of product, just different lengths and diameters. Here you have to choose types of drills on a tree, corresponding to all your tasks. Of course, in such a set there should be a twist drill for wood, the products are presented in a wide range - from 3 to 52 mm in diameter! good tool this kind should have a point, thanks to which it will not slip off the surface.
Products with a diameter of 10 mm or more must have a hexagonal shank so as not to rotate during operation. It is also important to know how many revolutions during drilling should correspond to a particular tool diameter. For example, if you are dealing with small products up to 14 mm, you should set no more than 1700-1800 rpm for soft woods and half as much when drilling hard woods. Working with tools with a diameter of 16 to 25 mm, on hard rocks, you should adhere to 500 revolutions, you can triple the speed when drilling soft rocks.
The larger the diameter, the lower the speed - by observing this ratio, you will prolong the life of the product for a long time! When choosing tools, pay attention to the color of the metal - if it is normal grey colour, then such a product has not been subjected to any additional processing, respectively, and it will not last long. Black color indicates processing with very hot steam, and yellow inherent in products that are treated with titanium nitride, which increases the service life at times.
Long drill bits for wood are very dependent on their diameter. You will not find thin and at the same time long products - than thinner tool, the shorter, otherwise it may break even with slight pressure. So, a ten-millimeter drill can be up to 45 cm long, while a twelve-millimeter drill can be all 60! Of course, it is absolutely not necessary to buy such long ones, unless you are dealing with drilling holes in thick bars.
Of course, you must also observe a healthy ratio between the capabilities of the drill itself and the dimensions of the drill, because a product 45 cm long and 52 mm in diameter will weigh almost 3 kilograms! An ordinary household drill will barely turn it even idle! Experienced Builders when working with such “giants”, even low-speed drill-mixers are used!
However, there is a trade-off between the ability to drill large diameter holes and the weight of the drill! Products of this type are called feather, since drilling occurs due to the "feather" of the desired diameter at the end of a long rod. On the market you will find tools from 10 to 55 mm. True, this compromise option also has significant drawbacks, compared to the same spiral ones - they do not have a chip outlet, which greatly complicates the process of working with deep holes. Most often, these are used for drilling not very thick boards, as well as fiberboard and chipboard, so they are produced up to 15-20 cm long. True, there are also extension cords with which you can make holes up to 40 cm deep!
As a rule, such tools have a hex shank to sit tight in the chuck. This option is perfect for holes under door locks. But you can work with them even not very powerful tools, and at a price they are much cheaper than spiral ones - sometimes the difference is 5-10 times! The recommended speed when drilling for hardwood with tools up to 25 mm is 1500 rpm, if drills of a larger diameter are reduced to 1000. Soft rocks can be drilled at 1500-2000 rpm.
Forstner drills are especially popular among furniture makers, because they can be used to drill a blind hole with a flat, even and smooth bottom. That is why such drills are often called plug drills, although in fact this definition does not quite fit them, because there are special products of a different design just for drilling plugs.
The diameter of the products is presented in the range from 10 to 50 mm. Quite often, the cutting edges are made of hard alloys, which significantly increases the service life of the product. As a rule, such drills are up to 10 cm long, although this parameter can be tripled with the help of extension cords. In operation, the recommended speed for soft woods ranges from 2500 rpm to 1000 rpm for large diameters, while hard rocks it is recommended to drill at sufficiently low speeds. For example, for tools with a diameter of 15 mm, it is recommended to set no more than 500 rpm.
External resemblance to the crown was the reason for the emergence of another name for such products - crowns. Their most important advantage lies in the ability to make holes of large diameters that even the largest twist or flute drills cannot make. Crowns look like a ring with teeth, usually sold in sets, as nozzles on one base, inside of which there is a center drill. Of course, such holes cannot be made too deep - conventional models are able to master material up to 22 mm, professional ones - up to 64 mm. In addition, such tools are effective when working with plastic and drywall.
It doesn't hurt to mention one more unusual view- Thermite drills, or, as they are called in a professional language, milling drills. Thanks to the characteristic appearance such products cannot be confused with anything - they have a monolithic tip, like a regular twist drill, and a core with multiple cutting edges. With the help of such tools, not only drilling is performed, but also milling - first we drilled, and then we go in the right direction. You can work with milling products both on wood and on plastic. Their diameter does not exceed 12 mm.
Long drill bits for metal are used to drill through holes as well as blind holes in spindles, shafts and parts with a long length. They are characterized by low productivity. Ground long drill for metal has high resistance to breakage, it is used when working with alloyed and unalloyed carbon steel, Petrometal non-ferrous metals, gray and malleable cast iron, cermets, bronze and brass. They are manufactured in accordance with GOST 886-77, GOST 886-77, GOST 2092-77 and GOST 22094-76. The GOSTs provide information on the main dimensions of the devices. They have a diameter of 1 to 20 mm, a total length of 56 to 254 mm. In them, unlike other cutting tools, the overall and working distance is increased, as well as the angle at the top of the cutting edges is increased. In all standard designs, it is 118 degrees, and in long devices - 135. This feature allows you to work with materials that are much heavier, as the load on the tool is reduced. This leads to an increase in the service life of the device, as well as an increase in the intervals between sharpening.
How to choose an elongated drill bit for metal?
When choosing an elongated cutting device, first of all, pay attention to the following details:
- Elongated twist drills;
- With a cylindrical shank.
Main dimensions
| Name | Diameter, mm | Length, mm |
|---|---|---|
| 1,5 | 70 | |
| Metal drill extended DIN 340 | 2 | 85 |
| Metal drill extended DIN 340 | 2 | 85 |
| Metal drill extended DIN 340 | 2,9 | 95 |
| Metal drill extended DIN 340 | 3 | 100 |
| Metal drill extended DIN 340 | 3 | 100 |
| Metal drill extended DIN 340 | 3,2 | 300 |
| Metal drill extended DIN 340 | 3,2 | 106 |
| Metal drill extended DIN 340 | 3,3 | 106 |
| Metal drill extended DIN 340 | 3,5 | 106 |
| Metal drill extended DIN 340 | 3,5 | 112 |
| Metal drill extended DIN 340 | 3,8 | 112 |
| Metal drill extended DIN 340 | 4 | 119 |
| Metal drill extended DIN 340 | 4 | 119 |
| Metal drill extended DIN 340 | 4 | 119 |
| Metal drill extended DIN 340 | 4,1 | 300 |
| Metal drill extended DIN 340 | 4,2 | 119 |
| Metal drill extended DIN 340 | 4,5 | 119 |
| Metal drill extended DIN 340 | 4,5 | 126 |
| Metal drill extended DIN 340 | 5 | 126 |
| Metal drill extended DIN 340 | 5 | 132 |
| Metal drill extended DIN 340 | 5 | 132 |
| Metal drill extended DIN 340 | 5,5 | 300 |
| Metal drill extended DIN 340 | 5,5 | 139 |
| Metal drill extended DIN 340 | 6 | 139 |
| Metal drill extended DIN 340 | 6 | 139 |
| Metal drill extended DIN 340 | 6 | 139 |
| Metal drill extended DIN 340 | 6,5 | 300 |
| Metal drill extended DIN 340 | 7 | 148 |
| Metal drill extended DIN 340 | 7 | 156 |
| Metal drill extended DIN 340 | 7,5 | 156 |
| Metal drill extended DIN 340 | 8 | 156 |
| Metal drill extended DIN 340 | 8 | 165 |
| Metal drill extended DIN 340 | 8 | 165 |
| Metal drill extended DIN 340 | 8,5 | 300 |
| Metal drill extended DIN 340 | 9 | 165 |
| Metal drill extended DIN 340 | 9 | 175 |
| Metal drill extended DIN 340 | 10 | 175 |
| Metal drill extended DIN 340 | 10 | 184 |
| Metal drill extended DIN 340 | 10 | 300 |
| Metal drill extended DIN 340 | 11 | 195 |
| Metal drill extended DIN 340 | 12 | 205 |
| Metal drill extended DIN 340 | 12 | 300 |
Manufacturers
The twist drill is produced in three countries:
- Russia;
- Germany;
- China
Most best devices manufactured in Germany by Heller, they have the greatest strength and service life.
How to choose a drill for metal: Video
- Angle of sharpening of the cutting part. At this device it should be 135 degrees.
- Marking. From it it will be clear what material the device is made of and how it can be used.
- Color. Choose rich gold cutting tools, as they have the strongest strength, and they also have the lowest friction.
- Manufacturing material. It affects the ability of the device to drill certain structures.
We also recommend that you pay attention to the model of your machine, its condition, power, the method of obtaining the workpiece (it can be casting, stamping, cutting), the accuracy of the resulting hole. Be sure to find out what tolerance and roughness the extra long drill has. Also consider the depth of the hole to be machined.
Types and specifications
The following cutting tools can have an elongated design:
- Elongated twist drills;
- Drills extended conical shank spiral;
- With a cylindrical shank.
Drills with a long series with a tapered shank have a special part of the tool that is clamped in the chuck of a drill or machine.
The length of the device is selected depending on the diameter of the hole, the size of the drill for metal elongated is not much larger than standard sizes.
There are also extra long drill bits for metal, they are used for drilling deep holes in steels that have a hardness of 1300 N / mm 2.
Main dimensions
In the table below you can find the main parameters of cutting tools with big size, namely with their diameter and length. For example, drill 5 5 long has a length of 139 mm.
photo: dimensions of elongated drills for metal
| Name | Diameter, mm | Length, mm |
|---|---|---|
| Metal drill extended DIN 340 | 1,5 | 70 |
| Metal drill extended DIN 340 | 2 | 85 |
| Metal drill extended DIN 340 | 2 | 85 |
| Metal drill extended DIN 340 | 2,9 | 95 |
| Metal drill extended DIN 340 | 3 | 100 |
| Metal drill extended DIN 340 | 3 | 100 |
| Metal drill extended DIN 340 | 3,2 | 300 |
| Metal drill extended DIN 340 | 3,2 | 106 |
| Metal drill extended DIN 340 | 3,3 | 106 |
| Metal drill extended DIN 340 | 3,5 | 106 |
| Metal drill extended DIN 340 | 3,5 | 112 |
| Metal drill extended DIN 340 | 3,8 | 112 |
| Metal drill extended DIN 340 | 4 | 119 |
| Metal drill extended DIN 340 | 4 | 119 |
| Metal drill extended DIN 340 | 4 | 119 |
| Metal drill extended DIN 340 | 4,1 | 300 |
| Metal drill extended DIN 340 | 4,2 | 119 |
| Metal drill extended DIN 340 | 4,5 | 119 |
| Metal drill extended DIN 340 | 4,5 | 126 |
| Metal drill extended DIN 340 | 5 | 126 |
| Metal drill extended DIN 340 | 5 | 132 |
| Metal drill extended DIN 340 | 5 | 132 |
| Metal drill extended DIN 340 | 5,5 | 300 |
| Metal drill extended DIN 340 | 5,5 | 139 |
| Metal drill extended DIN 340 | 6 | 139 |
| Metal drill extended DIN 340 | 6 | 139 |
| Metal drill extended DIN 340 | 6 | 139 |
| Metal drill extended DIN 340 | 6,5 | 300 |
| Metal drill extended DIN 340 | 7 | 148 |
| Metal drill extended DIN 340 | 7 | 156 |
| Metal drill extended DIN 340 | 7,5 | 156 |
| Metal drill extended DIN 340 | 8 | 156 |
| Metal drill extended DIN 340 | 8 | 165 |
| Metal drill extended DIN 340 | 8 | 165 |
| Metal drill extended DIN 340 | 8,5 | 300 |
| Metal drill extended DIN 340 | 9 | 165 |
| Metal drill extended DIN 340 | 9 | 175 |
| Metal drill extended DIN 340 | 10 | 175 |
| Metal drill extended DIN 340 | 10 | 184 |
| Metal drill extended DIN 340 | 10 | 300 |
| Metal drill extended DIN 340 | 11 | 195 |
| Metal drill extended DIN 340 | 12 | 205 |
| Metal drill extended DIN 340 | 12 | 300 |
Drilling deaf as well through holes in parts of great length causes the need for long drills for metal. Sometimes it's not possible to buy cutting tool the desired length, which entails the need to lengthen the existing one. How to lengthen a drill for metal and is it effective?
Ways to lengthen the tool, their features
Most of the ways to increase the length of a product are to attach an extension to its shank. The choice of a specific method should be based on the diameter of the tool, the availability of auxiliary equipment, as well as the desired final length.
The most common ways:
When lengthening the tool, remember that the part used as an extension should be chosen with a slightly smaller diameter than the drill. In addition, when working with a converted product, it is necessary to correct the cutting conditions when drilling.
Drills and accessories for drilling machines Metaltool
The Metaltool group of companies sells quality equipment and metal-cutting tools of the best domestic, world manufacturers, providing delivery across Russia, CIS countries.
Own brand core drills are reliable and productive, they can be used with turning, milling and drilling equipment. Qualified consultants will help in choosing products and placing an order, comment on the characteristics and advantages of the products offered. A long-term warranty will ensure the prompt replacement or repair of equipment and tools, and permanent promotions will be a pleasant bonus when buying.
