How Is The Torque Of A Screwdriver Measured?

Choosing a screwdriver

The choice of a screwdriver (cordless screwdriver) is a completely solvable task. To do this, you need to know what characteristics you need to pay attention to when choosing. To begin with, we decide whether a household or professional model is needed. If you buy a screwdriver for small housework, for work in the country, etc., then your choice is a household screwdriver. If the screwdriver is expected to be used intensively for a long time, then you need a professional screwdriver. This material will tell you how to choose a screwdriver.

Let’s go back to the main characteristics that you need to know when choosing a cordless screwdriver:

Screwdriver motor voltage. Modern models of screwdrivers have a motor voltage from 7.2V to 24V (Volts). The higher the voltage, the less current is needed to obtain the required power. Accordingly, more power is easier to get in a screwdriver with an 18V motor, and not 12V or 7.2V. It is worth clarifying that the most common screwdrivers with a 12V, 14V and 18V motor.

Screwdriver torque. Torque is measured in Nm (Newton per meter). In simple words, torque is the force with which your screwdriver twists the screws. The more torque, the more opportunities a screwdriver has. In modern household screwdrivers, the torque is usually 10-28 Nm. This is enough for housework. With a torque of 28-30Nm, the screwdriver can screw in 100mm self-tapping screws and drill wood with metal. Speaking of drilling in wood and metal, modern household models are capable of drilling holes up to 20mm in wood and up to 13mm in metal. In professional screwdrivers, the torque reaches 70-140Nm.

Most screwdrivers have a torque adjustment function. It is used where more control is required when performing certain jobs. Adjustment takes place by switching the ring located on the screwdriver body, at the base of the chuck. The numbers on the ring indicate the modes in the torque setting. The drill icon after the maximum number on the ring shows the drilling mode.

Using the example of screwing self-tapping screws, the function is used as follows:

Tightening screws of different lengths does not need one torque. For smaller self-tapping screws, a lower tightening force is sufficient, and for longer self-tapping screws, a correspondingly greater tightening force. Most likely everyone who has screwed a self-tapping screw into a tree at least once, but sunk it into the material. And where it is necessary that the surface is even and smooth, dents are not permissible. When the so-called “ratchet” is triggered, and this happens when the set torque is overestimated, the screwdriver stops tightening the screw. Thus, allowing more precise control over the work process. This function also protects the motor from overload.

Cordless screwdriver battery. It is the battery that allows you to work mobile and not depend on the length of the cord. Three types of rechargeable batteries are used in screwdrivers:

NiCd (nickel-cadmium). such batteries are the most affordable, but the characteristics are simpler than those presented below. The capacity of such batteries is from 1.2 or 1.5 A / h (Ampere hour). A screwdriver with a capacity of 2.0A / h under the same conditions can work longer than a screwdriver with a battery capacity of 1.2A / h. A capacity of 1.2-1.5A / h is enough for home use. And considering the current charging time of the battery is 1 hour, you will always have a “fresh” battery at hand. Cons: require a complete discharge.

NiMh (nickel-metal hydride). these batteries are more expensive, but their capacity is higher from 1.5 to 2.6A / h. Suitable for home use as well as for more complex and prolonged use. Does not require a complete discharge.

Li-Ion (lithium-ion). batteries are the most expensive, have a high capacity, which is higher than 3.0A / h. Another advantage of Li-Ion batteries is their light weight. The difference in weight can be up to 40%. Li-Ion batteries do not have a memory effect, which allows you not to wait until the battery is completely discharged.

It is worth saying that the warranty does not apply to batteries, since they often fail due to the fault of the buyer. If you leave the battery at a low temperature at least overnight and such batteries may not be used anymore. Store batteries in a warm room.

The number of revolutions of the screwdriver. For different types of work, different turns are needed. For drilling, higher speeds of 1000-1300rpm are required. To tighten the screws, 400-550 rpm is enough. Screwdrivers are available in single-speed, two-speed and three-speed. Gear shifting allows you to work with the speed you need to solve various tasks.

Quickset Adjustable Torque Screwdrivers (0.2. 9 N.m) by Torqueleader

So. If you choose a screwdriver for your home, then a 12-14V screwdriver with a battery capacity of 1.2-1.5A / h and a torque of 15-26Nm is suitable here. Such a screwdriver can handle almost any household work. Household screwdrivers with such characteristics are from 1300 to 3000 rubles. You should not chase a low price, as a rule, the price tag for a screwdriver below 900 rubles indicates that such a screwdriver will not work for a long time. When choosing, pay attention to the recognition of the manufacturer’s company, the terms of the guarantee, the number of service centers. Well, the screwdriver itself should be held in hand, turned, pressed, etc.

The maximum torque of the screwdriver is

Getting acquainted with the characteristics of any screwdriver, you will surely come across such a parameter as torque, which is measured in newton meters (Nm). Not everyone remembers from the school physics course what this means. And in this article I will try to explain what the torque of a screwdriver is.

In simple terms, the torque of a screwdriver means the maximum force that it can transmit to a screw or self-tapping screw. It is clear that the higher the torque, the more this force will be.

What does all this affect? To how much, for example, a large self-tapping screw or a screw in length and diameter you can screw into this or that material. Well, besides, if you take two screwdrivers with different torque and perform the same work with them, then the mechanism of the screwdriver with more torque will wear out less. Therefore, we can say that the amount of torque also affects the tool life.

What is Newton?

If you write “Newton” with a capital letter, then this is the name of the scientist, after whom the unit of measurement is named, by which force is measured.

Well, when it comes to the unit of measurement, then “Newton” is written with a lowercase letter, and denoted as “H”.

As a unit of measurement, scientifically speaking, 1 N is a force that changes in 1 second the speed of a body weighing 1 kg by 1 m / s in the direction of the force.

If it is somewhat simpler, then we can say this: for a body weighing 1 kg to move and increase its speed by 1 m / s with each second, then a force equal to 1 N must be applied to it.

Still not clear? Then take an object with a mass of 100 g in your hand. This is the force of gravity that attracts this object to the ground and will be approximately equal to one newton. Why about? Because the force of attraction at different points of the Earth is somewhat different and the standard of one Newton will be the gravity of a body weighing 102 g, located at sea level on the surface of the Earth at a latitude of 40 degrees.

And what is a newton meter?

Again, if you use a quote from Wikipedia, then “one Newton meter is equal to the moment of force created by a force of 1 N relative to a point located at a distance of 1 m from the mowing line of the force action”.

With regards to the screwdriver, I will explain it as follows. A screwdriver chuck has an axis around which it rotates. Take a screwdriver and place it horizontally with its axis of rotation. Then we take an L-shaped metal bar, in which one of the sides is 1 m long, and the other (no matter how long) will be clamped in the chuck. So, if the side of the bar, which is equal to 1m, is placed horizontally and a weight of 100 g is suspended on its opposite end from the screwdriver, then we will get a torque acting on the cartridge, approximately equal to one newton meter. And if you hang, for example, a load of 4 kg, then we get 40 Nm.

Therefore, if a screwdriver states, for example, that its maximum torque is 40 Nm, then this means that the screwdriver’s motor through the gearbox transfers to the chuck such a force as if we really assembled the above structure and suspended a load of 4 kg. We will not take into account the mass of the bar itself.

This is what the torque of a screwdriver is.

Well, in conclusion, I must say that the maximum torque is achieved by fully pressing the start button. In addition, on two-speed screwdrivers at different speeds, the torque will also be different. on the first more, on the second less.

Also, screwdrivers have a special regulator that has a scale with marks from 1 to 15, 20 or another number (as the manufacturer decides) and the last mark in the form of a drill (in this position, you can and should drill), which limits the torque. That is, if you set the regulator to one of the numerical marks, then when a certain value of the moment is reached, the screwdriver does not turn further, but clicks. But if you put the regulator in the “drill” position, then the screwdriver will not click, but will try to tighten what it turns to the last. At the same time, the above numbers do not mean the actual moment itself, but simply show how much more or less you do it (just to navigate faster when working)

See also  How to Install a Ratchet on a Screwdriver

I hope I managed to explain the essence of the torque of the screwdriver. On this I take my leave. until we meet again!

Torque is the main characteristic of a screwdriver. It determines the diameter of the screw and its screwing depth, as well as the material (wood, concrete, steel, etc.).

The torque is determined by the power of the tool, which depends on the engine and battery. The documentation for the device usually indicates the maximum possible diameter and length of the screw. At the same time, the maximum possible torque reaches 60 Nm, for a home tool it is 10-12 Nm.

The efficiency of a screwdriver is significantly increased if it can be used in a pulsed mode (chiseling like a hammer drill).

Types of screwdrivers

According to the power source used, the tool is:

Rechargeable. Cordless screwdrivers are used in everyday life and at work. Battery capacity is 1.5Ah and above, voltage is 10-12V (household) or 18-36V for professional. The most common are nickel / metal / hybrid batteries. Lithium and nickel cadmium are also used. The choice of a cordless screwdriver is very suitable for new buildings where power has not yet been supplied.

Torque Screwdriver Tester Product Video

Network screwdriver. Powered by a 220V network, the disadvantage is the presence of a network cable (length limitation, some inconvenience during operation).

Pneumatic used in series production, where there are permanent pneumatic power mowing lines.

By the type of work performed, screwdrivers are divided into two groups:

Household (home, amateur). They are used for a small amount of work. minor (episodic) repairs, one-time work (changing doors, assembling furniture).

Professional used for large volumes of work in construction, furniture production, etc.

Special attention should be paid to tools that combine 2 functions. drill screwdriver.

Choosing a screwdriver

First of all, you need to determine its exact purpose:

For home use a simple tool with max. torque 10-12Nm, voltage 12V and battery capacity from 1.2Ah.

For professional work the recommended parameters are as follows:

Max. torque. 60-120Nm;

battery capacity. more than 3Ah;

such tools are more expensive and require certain skills to operate.

If necessary, you can choose a combined tool. a drill screwdriver, which is often very convenient.

It is also necessary to pay attention to battery charging. If a household battery can be charged for 3-6 hours, then for a professional this time is 40-60 minutes. For reliable operation, it is recommended to have a set of 2 batteries.

The tool can be equipped with special gearboxes to reduce the speed of the electric motor. Gearboxes are usually planetary type, which are small in size, weight at a sufficiently high gear ratio. Such gearboxes easily switch to drilling (drill) mode. In modern screwdrivers there is a torque regulator that allows you to screw in the screws with the required force, which prevents thread stripping, grinding of splines and

First, a little background. When choosing a screwdriver, every slightly savvy user will certainly have a question about the torque that he can provide. On this forum, almost half of the topics are devoted to this issue, but there was no consensus. And this is connected, apparently, with the fact that every manufacturer understands by this term who is in what is much. And every tool seller also has his own opinion on this matter. The result is complete confusion. And if the soft / hard moment can still be found in the parameters of the instrument (Although who understands what by this and remains a mystery, therefore it is absolutely impossible to compare instruments by these parameters. For example, an instrument with a smaller soft moment for some reason, judging by the description, can drill holes of a larger diameter or screw in larger self-tapping screws (for some reason, without mentioning their length). Or the ratio of blocking moments at the 1st / 2nd speed does not correspond to the ratio of the speeds themselves. Miracles.), then the information about the range clutch actuation is a gloomy mystery. For some reason, almost all instrument manufacturers (with the exception of literally two or three brands) hide this parameter as a state secret. Although, it would seem, what is easier. trying on and listing in the catalog? I was interested in this question in the first place, since the torque limiting clutch is almost the main part of any screwdriver. At least that’s what makes it different from a regular drill.
In short, I decided to check everything myself. I started by looking for torque meters. Such things were found pretty quickly, but I was not ready for their cost. started at a thousand dollars. And then I decided to make such a device myself. In theory, there is nothing complicated here. What is 1 Nm torque? This is the moment created by a force of 1N applied to a 1m long arm. If to the end of a 1m arm we suspend a weight of 1kg, then we get a moment of 9.81Nm (since gravity = mg, and g = 9.81N / kg)). If this shoulder is reduced by 9.81 times, then 1kg will just create a torque of 1Nm. From here the diagram of the device is immediately obtained (see photo). We make a lever with a length of 10.2 cm and hook it to the usual steelyard. I used an electronic balance wheel with a range of up to 20kg, a graduation of 0.01kg and an accuracy of 0.02kg. Since the lever of the required length can be made quite accurately and it is easy to maintain the perpendicularity of the lever and the axis of the balance, the accuracy of our device will actually be determined by the accuracy of the balance. Thus, we have got a torque meter with a range of 0-20Nm and with an accuracy of 0.02Nm. Not every industrial design can boast of such parameters.
Unfortunately, it was not very good to measure the clutch actuation moment with such a device. When the clutch starts to work (crack), the moment starts to “jump”. And this electronic steelyer takes time to set the readings, i.e. it measures a certain average value, not the maximum, after which the clutch is triggered. Here we need, apparently, some kind of mechanical (non-inertial) balance bar with fixing the maximum value (well, that is, a peak detector). But this device measures the static moment very successfully. And then the results somewhat (to put it mildly) surprised and puzzled me.
I first tried to measure the maximum torque using a simple screwdriver, a pistol grip screwdriver and a small ratchet wrench (see photo). The results are as follows (and, I must say, quite expected):

  • simple screwdriver 3Nm
  • screwdriver with pistol grip 6Nm
  • ratchet wrench 12Nm
    And I really tried my best.
    I was surprised by the results of the screwdrivers in the “drilling” position. The spindle was tightly blocked and the static blocking moment was measured:
  • Metabo PowerMax (1st speed, “drilling”) 3.8 Nm (with passport data 15 Nm.). I thought the battery might be dead. I put it fully charged, it turned out 4.8 Nm and this moment fell before our eyes due to the discharge of the battery. On the next attempt, the same 3.8 Nm was obtained.
  • AEG BBS 14 KX Raptor (1st speed, “drilling”) 18Nm (with a static blocking torque according to the passport 40Nm.).
    And how do you order this to be understood?
    I’ll try again with the old Metaboy, I’ll bring it from the dacha.

Give all the shura to OlegCh for measurements! Find out the truth.

Calculation of the motor torque

The torque of an electric motor is the force of rotation of its shaft. It is the torque that determines the power of your engine. Measured in newtons per meter or kilogram-force per meter.

Types of torques:

  • Rated. torque value at standard operation and standard rated motor load.
  • Launcher is a tabular value. The rotational force that the electric motor is able to develop when starting. When selecting an electric motor, make sure that this parameter is higher than the static moment of your equipment. pump or fan, etc. Otherwise, the electric motor will not be able to start, which is fraught with overheating and burnout of the winding.
  • Maximum. the limit value, upon reaching which the load will balance the engine and stop it.

Torque Calculation. Formula

Note: when calculating, it is worth taking into account the slip coefficient of the induction motor. The nominal number of revolutions of the engine does not coincide with the real one. You can find the exact number of revolutions, knowing the marking, in the table above.

Motor Torque Table

This table contains the torques of the most common AIR electric motors in Ukraine, as well as the required at start-up. starting, the maximum allowable for this type of electric motor. the maximum torque and moment of inertia of AIR motors (the effort is important when selecting an electromagnetic brake, for example)

Engine kW / rev Mnom, Nm Mpusk, Nm Mmax, Nm Minn, Nm
AIR56A2 0.18 / 2730 0.630 1,385 1,385 1.133
AIR56V2 0.25 / 2700 0.884 1.945 1.945 1.592
AIR56A4 0.12 / 1350 0.849 1,868 1,868 1,528
AIR56V4 0.18 / 1350 1.273 2.801 2.801 2,292
AIR63A2 0.37 / 2730 1.294 2,848 2,848 2,330
AIR63V2 0.55 / 2730 1.924 4.233 4,233 3.463
AIR63A4 0.25 / 1320 1.809 3.979 3.979 3.256
AIR63V4 0.37 / 1320 2.677 5.889 5.889 4.818
AIR63A6 0.18 / 860 1.999 4.397 4.397 3.198
AIR63V6 0.25 / 860 2.776 6.108 6.108 4.442
AIR71A2 0.75 / 2820 2,540 6.604 6,858 4,064
AIR71V2 1.1 / 2800 3.752 8.254 9,004 6,003
AIR71A4 0.55 / 1360 3.862 8,883 9.269 6.952
AIR71V4 0.75 / 1350 5.306 13.264 13,794 12,733
AIR71A6 0.37 / 900 3.926 8.245 8.637 6,282
AIR71V6 0.55 / 920 5,709 10,848 12,560 9,135
AIR71V8 0.25 / 680 3.511 5.618 6.671 4.915
AIR80A2 1.5 / 2880 4.974 10,943 12,932 8.953
AIR80V2 2.2 / 2860 7,346 15,427 19,100 13,223
AIR80A4 1.1 / 1420 7.398 16,275 17,755 12,576
AIR80V4 1.5 / 1410 10,160 22,351 24,383 17,271
AIR80A6 0.75 / 920 7,785 16,349 17,128 12,457
AIR80V6 1.1 / 920 11,418 25,121 26,263 20,553
AIR80A8 0.37 / 680 5.196 10,393 11.952 7.275
AIR80V8 0.55 / 680 7,724 15,449 16,221 10.814
AIR90L2 3/2860 10.017 23,040 26.045 17,030
AIR90L4 2.2 / 1430 14,692 29,385 35,262 29,385
AIR90L6 1.5 / 940 15,239 30,479 35.051 28,955
AIR90LA8 0.75 / 700 10,232 15,348 20,464 15,348
AIR90LB8 1.1 / 710 14,796 22,194 32,551 22,194
AIR100S2 4/2850 13,404 26,807 32,168 21,446
AIR100L2 5.5 / 2850 18,430 38,703 44,232 29,488
AIR100S4 3/1410 20,319 40,638 44,702 32,511
AIR100L4 4/1410 27,092 56,894 65.021 43,348
AIR100L6 2.2 / 940 22,351 42,467 49,172 35,762
AIR100L8 1.5 / 710 20,176 32,282 40,352 30.264
AIR112M2 7.5 / 2900 24,698 49.397 54,336 39,517
AIR112M4 5.5 / 1430 36,731 73,462 91,827 58,769
AIR112MA6 3/950 30,158 60,316 66,347 48,253
AIR112MV6 4/950 40,211 80,421 88,463 64,337
AIR112MA8 2.2 / 700 30.014 54.026 66.031 42,020
AIR112MV8 3/700 40.929 73,671 90.043 57,300
AIR132M2 11/2910 36,100 57,759 79.419 43,320
AIR132S4 7.5 / 1440 49,740 99.479 124,349 79,583
AIR132M4 11/1450 72,448 173,876 210,100 159,386
AIR132S6 5.5 / 960 54,714 109,427 120,370 87,542
AIR132M6 7.5 / 950 75.395 150,789 165,868 120.632
AIR132S8 4/700 54,571 98.229 120,057 76,400
AIR132M8 5.5 / 700 75.036 135,064 165,079 105,050
AIR160S2 15/2940 48,724 97,449 155,918 2.046
AIR160M2 18.5 / 2940 60,094 120.187 192,299 2.884
AIR180S2 22/2940 71,463 150.071 250,119 4.288
AIR180M2 30/2940 97,449 214,388 341,071 6,821
AIR200M2 37/2950 119,780 275,493 383,295 16,769
AIR200L2 45/2940 146,173 380,051 584,694 19,003
AIR225M2 55/2955 177,750 408,824 710,998 35,550
AIR250S2 75/2965 241,568 628,078 966,273 84,549
AIR250M2 90/2960 290.372 784,003 1161,486 116,149
AIR280S2 110/2960 354,899 887,247 1171,166 212,939
AIR280M2 132/2964 425,304 1233,381 1488,563 297,713
AIR315S2 160/2977 513,268 1231,844 1693,786 590,259
AIR315M2 200/2978 641,370 1603,425 2116,521 962,055
AIR355SMA2 250/2980 801,174 1281,879 2403,523 2163,171
AIR160S4 15/1460 98,116 186,421 284,538 7,457
AIR160M4 18.5 / 1460 121,010 229,920 350,930 11,375
AIR180S4 22/1460 143,904 302,199 402,932 15,110
AIR180M2 30/1460 196,233 470.959 588,699 27,276
AIR200M4 37/1460 242,021 532,445 847,072 46.952
AIR200L4 45/1460 294,349 647,568 941,918 66,229
AIR225M4 55/1475 356,102 997,085 1317,576 145.289
AIR250S4 75/1470 487,245 1218,112 1559,184 301,605
AIR250M4 90/1470 584,694 1461,735 1871,020 467,755
AIR280S4 110/1470 714,626 2072,415 2429,728 578,847
AIR280M4 132/1485 848,889 1697,778 2886,222 1612,889
AIR315S4 160/1487 1027,572 2568,931 3802,017 2363,416
AIR315M4 200/1484 1287,062 3217,655 4247.305 3603,774
AIR355SMA4 250/1488 1604,503 3690,356 4492,608 8985,215
AIR355SMB4 315/1488 2021,673 5054,183 5862,853 12534,375
AIR355SMC4 355/1488 2278,394 5012,466 6151,663 15493,078
AIR160S6 11/970 108,299 205,768 314,067 12.021
AIR160M6 15/970 147,680 339,665 443,041 20.675
AIR180M6 18.5 / 970 182,139 400,706 546,418 29,324
AIR200M6 22/975 215,487 517,169 711,108 50.209
AIR200L6 30/975 293,846 617,077 881,538 102,846
AIR225M6 37/980 360,561 721,122 1081,684 186,050
AIR250S6 45/986 435,852 784,533 1307,556 440,210
AIR250M6 55/986 532,708 1012,145 1811.207 633,922
AIR280S6 75/985 727,157 1454,315 2326,904 1090,736
AIR280M6 90/985 872,589 1745,178 2792,284 1657,919
AIR315S6 110/987 1064,336 1809,372 2873,708 4044,478
AIR315M6 132/989 1274,621 2166,855 3696,400 5735,794
AIR355MA6 160/993 1538,771 2923,666 3539,174 11848,540
AIR355MV6 200/993 1923,464 3654,582 4423,968 17118,832
AIR355MLA6 250/993 2404,330 4568,228 5529,960 25485,901
AIR355MLB6 315/992 3032,510 6065,020 7278,024 40029,133
AIR160S8 7.5 / 730 98,116 156,986 235,479 13.246
AIR160M8 11/730 1007,329 1712,459 2417,589 181,319
AIR180M8 15/730 196,233 333,596 529,829 41,994
AIR200M8 18.5 / 728 242,685 509,639 606,714 67,952
AIR200L8 22/725 289,793 579,586 724,483 88,966
AIR225M8 30/735 389,796 701,633 1052,449 214,388
AIR250S8 37/738 478,794 861,829 1196,985 481,188
AIR250M8 45/735 584,694 1052,449 1520,204 695,786
AIR280S8 55/735 714,626 1357,789 2143,878 1071,939
AIR280M8 75/735 974,490 1754,082 2728,571 1851,531
AIR315S8 90/740 1161,486 1509,932 2671,419 4413,649
AIR315M8 110/742 1415,768 2265,229 3964,151 6370,957
AIR355SMA8 132/743 1696,635 2714,616 3902.261 12215,774
AIR355SMB8 160/743 2056,528 3496,097 4935,666 18097,443
AIR355MLA8 200/743 2570,659 4627.187 6940,781 26991.925
AIR355MLB8 250/743 4498,654 7647,712 10796,770 58032,638
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Online calculation

To calculate the torque of the electric motor online, enter the value of the electric motor power and the real angular velocity (number of revolutions per minute)

there will be a calculator

After calculating the torque, look at the diagrams for connecting asynchronous electric motors with a star and a triangle on the website of the Slobozhansky plant

Main technical characteristics of cordless drills

1.1. Torque

It characterizes the force of the electric motor forcing the chuck shaft to rotate. The higher it is, the denser material you can work with, the easier it is to tighten fasteners, tighten long self-tapping screws and unscrew jammed nuts. The torque values ​​in a household tool, which are used at home for one-time tasks, are quite sufficient in the range of 10. 15 Nm. With professional 2- and 3-speed cordless screwdrivers, this parameter exceeds 130 Nm to easily cope with drilling in very hard materials. Semi-professional models are able to develop this indicator up to 50. 80 Nm. For example, with a torque of 80 Nm, the tool can be used to screw self-tapping screws into metal.

When working with different types of fasteners, it is not so much effort that is important as delicacy. The torque value is selected depending on the diameter and length of the fastener and the material to be worked with. The design of the tool specifically for this purpose provides a torque limiter. a ring located after the chuck (Fig. The device of cordless drills-screwdrivers). In order not to rip off the screw head or slot and save the bits, set the required value on the ring before screwing the fasteners. As soon as the fasteners are screwed in and the desired value is reached, the chuck stops, although the engine continues to rotate. Incorrectly set torque threatens with a torn slot or head of the fastener, sinking it too deep into the surface and wearing out the bit. The torque limitation is set in steps. according to the division on the ring, corresponding to the rotation mode and force, so that the user has the opportunity to fine-tune the tool for a specific task. For household models, the number of steps can be 10, for professional models. up to 20.

1.2. Rotational speed

Shows the number of spindle revolutions per minute and defines the range of tasks that are performed at different speeds. The harder the material, the higher the rotation speed characteristic should be, the higher the rotation speed, the easier it is for the tool to cope with drilling. The parameter is directly related to the scope of use. It is not so much the maximum performance that is important here, but the ability to choose the operating mode. Firstly, it allows you to tune the tool to perform a specific task, and secondly, it allows you to save battery power. The drill driver can have 1, 2, 3 or 4 speeds. The first is the lowest, used to work with fasteners. For example, 400. 450 rpm is sufficient to screw in screws when installing hinges on a kitchen cabinet door. The second and third speeds are included when the tool is used as a drill. For drilling, an indicator of 1000 rpm is required.

1.3. Battery specifications

Determine the principle of operation of cordless drills and screwdrivers and affect the power of the tool and the duration of work. The type of battery and its parameters determine the duration of operation on a single charge, the speed of its discharge, the risk of heating during operation and even the convenience of the tool in principle. When choosing a battery, they look at its resistance to self-discharge, low temperatures and the memory effect.

torque, screwdriver, measured

Battery type

  • They have no memory effect, are not subject to self-discharge, but lithium-ion batteries are more sensitive to cold than other types. They are characterized by increased capacity, low weight and high price. The number of charge / discharge cycles is 3 times more than that of nickel-cadmium.
  • They are cheap, so they are more common than others, they are not afraid of frost, but they have a strong self-discharge and have a memory effect nickel-cadmium batteries. They must be completely discharged before storing and recharging, otherwise their capacity will decrease. By the way, these batteries are toxic in production and difficult to dispose of.
  • Eco-friendly in production and easy to dispose of, without memory effect and self-discharge, with small dimensions and weight, nickel-metal hydride batteries are not resistant to low temperatures and have a high price. Must be fully charged before storage, unlike previous batteries.

The capacity indicates the potential of the battery, i.e. the time during which it will be able to supply the load. The larger this value, the longer the operation of the screwdriver will be without recharging. Battery capacity decreases over time.

The voltage is summed at the output, since the battery consists of several power supplies connected by plates. The higher the voltage, the longer the drill will run at maximum speed.

1.4. Additional tool functions

If structures are to be dismantled, for example, the reverse function makes it possible without serious effort to unscrew the fasteners or release the drill jammed in the material. When drilling bricks and lightweight concrete, the impact function is indispensable. In pulse mode, the tool jerks. The inrush current principle significantly increases the torque. However, this mode, like the shock mode, quickly wears out the motor, so it is not recommended to use them often and a lot. The coasting brake allows the engine to stop running immediately after the engaging button is released. This eliminates the inertial run of the cartridge and makes the work more convenient: you can immediately proceed to the next self-tapping screw, and not wait a few seconds until it stops completely to get into the slot. Add-ons such as automatic spindle lock for easy tool change, built-in backlight, battery indicator are no longer features of a professional tool. they just make the work user-friendly and are present in most models.

Cordless Drill Specifications

The wide scope of application of the tool is due to the advantages, including mobility, which means the ability to work in any hard-to-reach places without being connected to the mains, and low weight. The cordless drill is used for screwing and unscrewing self-tapping screws, bolts, screws, screws, tightening dowels and anchors. The tool is effective for drilling soft and hard wood, plastics, drywall, soft metals. If the drill is equipped with an impact function, it can cope with the stuck fasteners and drill holes in brick and concrete. With the help of special nozzles, the old paint is removed with the tool, the surfaces are cleaned and polished. Like most types of tools, screwdrivers are divided into professional. models with high technical characteristics and significant resource, and household, designed for light loads from time to time. In order to choose a tool that will meet your expectations and spent funds, we will understand the device and the range of performance.

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The device of modern models and their principle of operation

Drilling and screwing fasteners requires short time intervals and relatively low power input. In such an intermittent mode, when the phases of work and rest alternate, cordless drills are preferable. Very small and easy to handle, they may differ slightly in design, namely, in the position of the handle. The figure below shows a model with a center of gravity handle, the most common for this tool. And the pistol grip, shifted back, is considered more ergonomic for drilling.

Under the housing there is an electric motor, a gearbox, a chuck and a battery. The new generation tools are equipped with a modern brushless motor. These are motors without collector brushes, which are the main wear parts. Therefore, this design contributes to higher efficiency and a long service life. The principle of operation of cordless drills begins with the operation of the engine. From it, the shaft begins to move through the gearbox. A metal gearbox is essential if you are choosing a tool for intensive, hard work with maximum load. The metal is better at dissipating heat, which ultimately has a beneficial effect on the durability of the tool. A plastic gearbox can be found both in cheap household models and in semi-professional ones, so be guided by the intended work. A chuck with a nozzle fixed in it is driven by the shaft. In cordless drills, as well as in a cordless tool, two principles of fixing the equipment are implemented. To install the drill into the key chuck, you need a special toothed key. In the chuck, the sleeve is tightened by hand without much effort on the part of the user. As you can see, the internal circuit of cordless drills is simple. As for operation, before starting work, check whether the battery is charged, install the desired nozzle and set the performance with a torque limiter. By the way, the clutch can be locked with an additional switch position. In this position, the torque is maximum and is necessary, for example, to create holes with large diameters or large depths. It should be remembered that the modes are set on the instrument only when it is turned off; during operation, no settings are made.

Choosing a cordless drill for home or work? Our site contains a huge selection of household and professional class models for furniture assembly, construction and finishing works, inexpensive options for home repairs. You can compare the characteristics yourself, look at articles, call the manager for advice. Make your choice and let the tool be your faithful assistant in the implementation of your plans.

What is more important in the characteristics of the car. horsepower or engine torque

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In order to understand this issue, you must first understand the concepts. So horsepower is actually relatively simple. This is the direct power that the power plant is capable of producing. Experts measure engine power not in “horses”, but in kW for greater accuracy. But we’ll talk about the nuances associated with engine power a little later.

Now for the torque. This indicator is the force with which the shaft of the power plant rotates. It is measured in Newton per meter. In fact, 1 newton per meter is the force required to rotate a pole with a weight of 100 grams attached to it. Thus, I personally assume that the higher the torque, the better. Certainly so, but there is a nuance that is best disassembled with an example.

An adult man, while pedaling a bicycle, creates a torque in the range of 130-150 Nm. This is almost the same as the MPI engine for the Skoda Fabia. At the same time, it is quite obvious that with the same torque, the car accelerates and travels much faster than a bicycle, despite the significantly greater mass. How so? This is because in addition to the engine torque, the rpm is also important, which is quite strongly tied to the power of the power plant. The cyclist makes 30-40 rpm, while the MPI engine makes up to 4 thousand rpm.

And here we smoothly come to another nuance associated with horsepower, which was already mentioned at the very beginning. The fact is that the engine power indicated in the characteristics of the vehicle (on paper) is not at all equal to the engine power during operation. The power produced varies greatly in accordance with the rpm produced. For example, the engine can deliver 63 kW at peak. However, with a relatively low turnover of 2.5-3 thousand per minute, it will only deliver power of 26-32 kW. All these indicators can vary in the most serious way depending on the model of a particular installation, in particular on what kind of fuel it uses. The higher the power of the unit at low revs, the better for the car in terms of its dynamics. Accordingly, the more complex and expensive such an engine is and the faster it wears out.

The bottom line is that for budget and even more prestigious cars, all this has very little value. By and large, when dealer companies indicate parameters such as horsepower, torque, etc. in the characteristics. all this is nothing more than a marketing ploy in order to seduce a potential buyer with beautiful numbers. All the above parameters of the power plant are of real importance only for professional racing cars.

In continuation of the topic, there is such a “five” cars. who turned out to be too innovative for their time.

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What is torque

Torque is a specification that indicates the force of the tool being loaded. On average, this indicator fluctuates around 5-10 Nm, which makes it possible for the master to solve various technical problems.

Such a load is typical for domestic household and semi-professional screwdrivers. This rotational force is enough to screw in bolts and self-tapping screws, stir the solution, drill metal plates of medium thickness.

What torque is the right tool for most problems? The answer to this question depends on where and how you intend to use the tool. For example, if the user needs a universal device with which he can perform various tasks. Then it is better to purchase a tool with maximum rotating force. Such a tool can screw screws of any length, even into hard materials (metal, hard wood, plastic).

Screwdriver torque

If the user purchases a screwdriver for working with ordinary wood, a tool with a minimum rotation rate is suitable for him. Even 500 rpm devices can drive screws. For more difficult surfaces it is better to choose a 1300 RPM tool. This screwdriver can drill the toughest materials.

Types of screwdrivers

Screwdrivers are widely used in various fields:

  • in construction;
  • in the decoration of premises;
  • in the production and installation of furniture, suspended ventilation systems, etc.;
  • in the repair of cars and other equipment.

All modern screwdrivers are divided into two groups depending on the power supply method:

  • Battery powered devices. Such units are heavy due to the battery. However, their important advantage should be considered mobility (this is an important quality for installation work).
  • Devices powered by the electrical network. These systems are very powerful, but can only be used near an outlet.

Cordless screwdriver

When choosing a tool, first of all, you should pay attention to the rotation speed. This characteristic will allow you to understand exactly how a particular model can be applied.

What is the torque of a screwdriver and what should it be

If you need to tighten a screw or bolt, a screwdriver will help speed up the process. This compact device, powered by mains or battery, has enough power to work with fasteners. An important characteristic of the tool is the torque of the screwdriver.

It is this parameter that you should pay attention to when choosing a specific tool.

Rotational speed and screw diameter

When buying a screwdriver, you need to separately evaluate the ratio of the screw diameter to the rotational speed. To do this, you need to know that:

  • For screws with a diameter of 6 mm, the tightening speed will correspond to 10 Nm. over, this indicator can vary depending on the rigidity of the material. So in some cases it can go up to 25 Nm.
  • If a screw with a 7 mm diameter is used, then the torque is 27 Nm for hard materials and 11 Nm for soft materials.
  • With a screw diameter of 8 mm (largest value), the torque reaches 30 Nm.

Correctly selected torque indicator will allow the master to quickly perform the necessary work. Such a tool will last longer and will fail less often. The higher the torque, the less effort the master has to apply.

Torque power is not so important for mains powered tools. But for cordless screwdrivers, this is a very important parameter, which determines how quickly the battery will sit down.

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