What is Wrench: Definition and 54 Discussions

A wrench or spanner is a tool used to provide grip and mechanical advantage in applying torque to turn objects—usually rotary fasteners, such as nuts and bolts—or keep them from turning.
In the UK, Ireland, Australia, and New Zealand spanner is the standard term. The most common shapes are called open-ended spanner and ring spanner. The term wrench is generally used for tools that turn non-fastening devices (e.g. tap wrench and pipe wrench), or may be used for a monkey wrench—an adjustable pipe wrench.In North American English, wrench is the standard term. The most common shapes are called open-end wrench and box-end wrench. In American English, spanner refers to a specialized wrench with a series of pins or tabs around the circumference. (These pins or tabs fit into the holes or notches cut into the object to be turned.) In American commerce, such a wrench may be called a spanner wrench to distinguish it from the British sense of spanner.
Higher quality wrenches are typically made from chromium-vanadium alloy tool steels and are often drop-forged. They are frequently chrome-plated to resist corrosion and for ease of cleaning.
Hinged tools, such as pliers or tongs, are not generally considered wrenches in English, but exceptions are the plumber wrench (pipe wrench in British English) and Mole wrench (sometimes Mole grips in British English).
The word can also be used in slang to describe an unexpected obstacle, for example, "He threw a spanner in the works" (in U.S. English, "monkey wrench").

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  1. jeff einstein

    B Will the wrench move clockwise?

    Hey There, I was just thinking up some ideas for machines that are independent of the ground to use in my work shop. I came across an idea but still haven’t made the machine, the machine is placed on the shaft of the wrench. I would like to know if this machine can successfully turn the...
  2. E

    What kind of wrench or tool can force open a door knob?

    One time a door got locked with the keys inside. I tried to kick the door open, but it can't even open. I saw in the movie they just kicked door once to open a door, it may not be true, unless you are the Rock. I know the lock services can open it using some kind of keys. But one time they...
  3. Y

    How to Convert Whitworth Wrench Sizes to AF

    Hi I'm trying to understand how to convert Whitworth Wrench sizes to across the flats (AF) sizes. I understand what Whitworth is, but I can't find any mathematical formula how to convert and perform the calculation yourself. When I look online, all I see are conversion tables, no formulas. I...
  4. H

    I Torque without a torque wrench

    I need to tighten the nut for a trailer hitch ball to 250 ft lbs but I don't have a torque wrench that can do it. I read on a different forum that an alternate old school method to get 450 ft lbs of torque is: Torque = Force x Distance So in that forum's example, have a 180 lb person stand on...
  5. J

    Impact Torque wrench on tire nut

    A car service center used a hydraulic impact torque (is this the one used?) on the car tire nuts. See video. The car tire nut are rated at 88 ft lbs torque. What is the estimated torque in the hydraulic impact torque? Could it be double or more? I know he should have used a torque wrench but...
  6. R

    Determining moment (or torque) around a certain point on a wrench

    Here's a diagram of the problem. There are 3 possible solutions: 163 in-lb clockwise, 163 in-lb counterclockwise, 82.7 clockwise or none of them. After attempting the problem the closest I got to was 82.7 but that was wrong so I'm still stuck.
  7. V

    Magnetism lab involving a nail and an Allen wrench

    So basically what I had to do was: 1. take a Allen wrench and let it come in contact with an iron nail. Nothing happened here. None of the objects are magnetic. 2. take the Allen wrench and let it touch the North end of a magnet. Then let the wrench come in Contact with the iron nail. Here the...
  8. S

    Automotive Single Setting Torque Wrench with extension calculations

    All, I have been going back and forth in my head on if I should shorten my extension or increase it and I need a second opinion to straighten me out. PN: 5T-I-SET https://snaponindustrialbrands.com/DSN/wwwsnaponindustrialbrandscom/Content/PDF/Snap-on%20Industrial%20Brands%20CAT4%20113.pdf Its...
  9. T

    Calculating Torque on a Wrench

    Homework Statement (a) Suppose you have just barely loosened a rusty bolt. Your mass is 80 kg and you have a wrench of length L = 50 cm placed as shown in the diagram below, and hung off the end so all your weight was applied, in the downward direction, to the end of the wrench. What is the...
  10. S

    Statics: pipe wrench gripping pipe

    Homework Statement A 500N force is applied to the handle at point F. The geometry & measurements are as given in the illustration. Find Cx, Cy, Ax and Ay[/B]Homework Equations Well, the 500N force produces a 200Nm torque at point D, since DF is 400mm. [/B]The Attempt at a Solution So the...
  11. korwynkim

    How is torque actually measured when using a torque wrench?

    Take this picture for example. Assume this picture represents a torque wrench applying torque on a nut, and a force F is applied at the centre of the black handle perpendicular to it. The force applied to the nut is: Torque = Fd There are times when a nut is in a very inconvenient location...
  12. P

    Finding the Force on a bolt from a wrench

    Homework Statement In an Effort to tighten a bolt, a force F is applied to the end of a wrench that has a length L perpendicular to the wrench. If the bolt itself has a radius of b, how much force is applied to the bolt Homework Equations ∑τ=RFsinθ ΣF=ma ∑T=Iα The Attempt at a Solution I...
  13. L

    Backwards extension torque wrench formula + cheat sheet review

    Hello! I took a quality certification test yesterday and there was a question on there about torque wrench formulas. I didn't have anything about that in my notes, so I took some time this morning to create a cheat sheet based on what I could find on the web. 1) In some of the forums, they...
  14. NewProgramma

    Torque/Moment of a bent wrench question

    Hi everyone, The problem below kinda confuses me...i've spend half an hour staring at this problem lol. Homework Statement : Q: A bent wrench is used to apply a moment of 221 Nm to the hexagonal nut. If the applied force F is 507 N and the angle θ is 21°, find the distance d. Answer in metres...
  15. J

    Astronaut throwing a Wrench in space problem again

    Homework Statement An astronaut with a mass of 90 kg (including spacesuit and equipment) is drifting away from his spaceship at a speed of 0.20 m/s with respect to the spaceship. The astronaut is equipped only with a 0.50-kg wrench to help him get back to the ship. Homework Equations...
  16. R

    Is an Automated Tapping Device the Solution to My Flowmeter Issue?

    I am looking for some device that can emulate someone tapping with a wrench every 20 minutes. More specifically, I have noticed that in my application, my flowmeters (rotameters) are dropping over time. As a workaround I have been able to tap them with a wrench every 20 to 30 minutes, this...
  17. M

    What is the recommended wrench clearance according to TEMA Table D5?

    I am trying to obtain minimum recommended wrench and nut clearances from TEMA Table D5, but I don't really know what quantity from this table I should be using.
  18. B

    Coefficient of friction between wrench jaws and cylinder

    Homework Statement The figure shows an adjustable pipe wrench, drawn to scale. The geometry of the mechanism is arranged so that the jaws clamp more tightly as force is applied to the handle. Friction between the jaws and the pipe transfers a torque from the jaws to the pipe. Find the critical...
  19. T

    Can an Allen Wrench Withstand Maximum Force Before Breaking?

    Hello, I was wondering if anyone here knew of (or could come up with) an equation relating the tensile strength and the maximum force that could be applied to an allen wrench? Any help is appreciated.
  20. I

    Line of action for which the resultant force of the wrench passes

    In tightening a bolt whose center is at point O, a person exerts a 180-N force on the ratchet handle with his right hand. In addition, with his left hand he exerts a 90-N force as shown in order to secure the socket onto the bolt head. Determine the equivalent force–couple system at O. Then find...
  21. J

    What is the difference in torque produced by a wrench versus a belt?

    Hello All I have recently been trying to get my head around torque and think I am getting there. but I am struggling to understand the different of using a wrench to move an object i.e a bolt and using a belt to move something ok i.e an alternator. I don't get is it the entire lenth of...
  22. L

    EoM for rigid body, wrench and twist help

    I am currently working on a robotic manipulation problem and need to form a model for how an object responds. I start by writing up the equations of motion for the body, the motion is then constrained by an additional constraint equation. However, I am new to the notions of twists and wrenches...
  23. Y

    Finding the magnitude of the moment on a pipe wrench

    Homework Statement A force of 56 pounds acts on the pipe wrench shown. find the magnitude of the moment about O by evaluating || OA x F || Homework Equations || OA x F || The Attempt at a Solution First I tried to find my vector component for Force which I got -56 [ cos(30)i +...
  24. 7

    Simplification of a Force and couple system Wrench Problem

    Homework Statement The Attempt at a Solution I understand 90% of the problem and how to do it, I just can't wrap my head around how they managed to get 0.3sin30 for that one side in the problem.
  25. S

    Understanding Torque: Solving a Wrench Homework Question

    Homework Statement Here it is http://i.imgur.com/pAegjId.png Homework Equations Torque = Distance * Force The Attempt at a Solution I have a problem with the second question in the problem. What does it mean?
  26. Saitama

    Solving the Mystery of Wrench Work Ratios

    Homework Statement (see attachment)Homework Equations The Attempt at a Solution If a force a F acts on the farther end of the wrench, the torque due to it Fl where l is the length of wrench. The work done by this torque for one full turn is Fl*(2##\pi##) For wrench A, l=10 cm, and for wrench B...
  27. D

    Calculating Force for Spark Plug Installation

    You are installing a new spark plug in your car, and the manual specifies that it be tightened to a torque that has a magnitude of 45.0 N*m. Using the data in the figure below (L = 0.300 m and ? = 52.6°), determine the magnitude F of the force that you must exert on the wrench. Relevant...
  28. J

    Calculate moment of a special wrench

    Homework Statement The specialty wrench shown in the figure is designed for access to the hold-down bolt on certain automobile distributors. For the configuration shown where the wrench lies in a vertical plane and a horizontal 200-N force is applied at A, perpendicular to the handle...
  29. S

    Does Leaving Torque Wrenches at High Settings Affect Calibration Accuracy?

    Hi, I hope this is in the correct section, please feel free to move it or advise me to move if it's in the incorrect section. I work as an aerospace engineer and a sideline of what i do is to maintain the torque wrenches we use on the equipment. We have a set schedule for maintenance every...
  30. R

    Quick help need with finding the MAGNITUDE of the TORQUE of this wrench

    I tried using Frsin θ (270.756)(46 cm)sin (68) but I got 11547.86 And got it wrong... And then I tried doing. 101.426982807+251.040591727 = 352.4 N*m but I got it wrong. ^ I don't remember how I did that but it was saved in my notes. Help?
  31. N

    Tool for combining forces/couples and reducing to a wrench

    This might be of interesting to beginning mechanical engineering students. If you're familiar with equivalent systems of forces and couples, any system can be reduced into a single force and single couple that's parallel to the force--a.k.a. a "wrench." I made a 3D visualization for reducing...
  32. N

    Replace the system of two forces and once couple by a Wrench

    *The title for this question is incorrect. I messed it up with another question. My apologies. Homework Statement Replace the system of two forces and one couple shown in Prob. 2/158 by a wrench. Determine the magnitude of the moment M of the wrench, the magnitude of the force R of the...
  33. N

    Determine the coordinaes of the x-y plane through which the wrench passes

    Homework Statement In tightening a bolt whose center is at point O, a person exerts a 56-lb force on the ratchet handle with his right hand. In addition, with his left hand he exerts a 10-lb force as shown in order to secure the socket onto the bolt head. Determine the equivalent force-couple...
  34. A

    The Spaceship and The Wrench (1/2 + 1/2 = 4/5)

    Background This started out as a question, but answered itself in the process of being written up. I thought I'd post it anyway, in case it might help clarify something for someone else. It is an alternative derivation of the solution to a (similar) question asked in Six Not-So-Easy Pieces...
  35. M

    Adding a wrench to a series circuit ?

    If someone could also clarify how to go about this one. Does the wrench added make it a parallel circuit? I found the voltage of the initial circuit by simply doing V = IR = (3)(10) = 30 V. The current flowing through the 4 ohm resistor must be the same as before... so the current for...
  36. P

    Torque wrench + multiplier + crows foot

    I've got a torque wrench attached to a multiplier that is attached to a crows foot, and I'm trying to spec the input torque (at the wrench head) that will give us a corresponding output torque (at the crows foot). I am aware of the calculations that need to be made when a crows foot (alone)...
  37. F

    Energy problem-worker on roof of a building dropped a wrench over the edge

    Homework Statement a worker on the roof of a building that is under construction dropped a 0.125 kg wrench over the edge. another workman on the 8th floor saw the wrench go by and determined that its speed at that level was 33.1 m/s. the first floor of the building is 12.0m high and each...
  38. T

    Calculating new torque on a modified wrench

    I am a Nuclear Reactor Mechanic in the US Navy, and I have run into a disagreement between my peers and I on the proper use of torque wrenches. The situation is simple... (NOTE: these numbers are arbitrary for consistency) You have a dial type torque wrench with a 1 foot handle and you apply...
  39. O

    Astronaut and Wrench Momentum Problem

    Homework Statement An astronaut of mass 76.0 kg is taking a space walk to work on the International Space Station. Because of a malfunction with the booster rockets on his spacesuit, he finds himself drifting away from the station with a constant speed of 0.530 m/s. With the booster rockets no...
  40. D

    Astronaut traveling at constant speed, throws a wrench

    1)Homework Statement An astronaut of mass 82.0 kg is taking a space walk to work on the International Space Station. Because of a malfunction with the booster rockets on his spacesuit, he finds himself drifting away from the station with a constant speed of 0.600 m/s. With the booster rockets...
  41. J

    Torque Wrench Tool Calculation

    Hello- I have a problem with a calculation regarding a mechanical tool, so I hope that this forum section is the proper place to post this message. If not, please let me know where would be best. Some background... In automobile mechanics, construction, etc., a torque wrench is a socket...
  42. S

    Physical pendulum wrench oscillations

    Question Details: A 1.44 kg monkey wrench is pivoted at one end and allowed to swing as a physical pendulum. The period of its motion is 0.860 s, and the pivot is 0.290 m from the center of mass of the wrench. (a) What is the moment of inertia of the wrench? 0.0767 kgm2 If the wrench is...
  43. H

    FEM/FEA Calculations for Torque Wrench 2NM-30NM

    Hope this is the right place for this? I have a torque wrench, and need to calculate several parameters. I need to calculate - Stress - Displacement and - Force required to reflect the torque rang (2NM - 30NM) I have ansys (fea) and mathcad (fem) at my disposal to do these...
  44. C

    Calculating Max Torque and Shaft Twist for Socket Wrench

    Homework Statement The steel shaft of a socket wrench is 18mm diameter and 450mm long. If the allowable shear stree is 70 MN/m^2. Homework Equations i) What is the maximum permissible torque T that may be extered with the wrench? ii) Through what angle (theta) in radians will the shaft...
  45. L

    Calculate Min Angle to Exert 35.0 NM Torque with 355 N Force

    Homework Statement You want to exert a torque of at least 35.0 N·m on a wrench whose handle is 0.150 m long. If you can provide a force of 355 N to the end of the wrench, what is the minimum angle at which you can apply the force in order to achieve the desired torque? Homework Equations...
  46. J

    What is the displacement of the wrench?

    Homework Statement a worker drops a wrench from top of building under construction. if g =9.8N/kg [down], after 7 seconds, what is the displacement of the wrench? Homework Equations The Attempt at a Solution i don't know the formula, totally lost
  47. Saladsamurai

    Another reduction to Wrench

    This one is really discouraging me. It looks sooooo easy since the forces are each in one direction The way I have usually handled these as a procedure is: Find F_r and then find M_r about some point and then decompose M_r into components that run parellel and perpendicular to F_r. Then I...
  48. Saladsamurai

    How Do You Convert Forces into a Wrench in Vector Mechanics?

    [SOLVED] Reduction to a Wrench So far I have moved the forces to point O where \sum F=F_r=-10.0\hat{j} I have also re-written each force in Cartesian-vector form where F_1=10[\frac{6i-6j}{\sqrt{72}}=7.071i-7.071j F_2=-10j and F_3=-F_1=-7.071i+7.071j. I am told to decompose each...
  49. M

    Solve 100J Torque Problem with a 30cm Wrench and Force Vector

    A wrench 30cm long lies along the positive y-axis and grips a bolt in the origin. A force is applied in the direction < 0; 3; -4 > at the end of the wrench. Find the magnitude of the force needed to supply 100J of torque to the bolt. how can i solve it? r=<0,.3,0> F=<0,3,4> T= r X F...
  50. W

    Wrench torque to remove nut

    1. If the torque required to loosen a nut is 40.0 mN, what miminum force must be exerted by a mechanic to the end of a 30.0 cm wrench to remove the nut? 2. A uniform bridge 20.0 m long and weighting 4.00 x 10^5 N is supported by pillars located 3.00 m from each end. if a 1.96 x 10^4 N car is...