What is Bolts: Definition and 56 Discussions

Udo Bölts (born 10 August 1966) is a retired German racing cyclist, the brother of Hartmut Bölts. Bölts confessed publicly in 2007 to having used EPO and growth hormones in 1996 and 1997.

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  1. D

    Help me understand how bolts take less load than members

    Hello, I am studying through a machine design book and ran across this confusing statement which summarizes the results of an example problem. The problem has a bolt and nut that together hold two members in compression. The stiffness ratio is given as $$K_m = 6K_b$$. The bolt is preloaded with...
  2. C

    Difference in clamping force between bolts and screws

    Hi everyone, I’m trying to figure out the clamping force of a set of screws that thread into a plate. My question is: Would this calculation differ from calculating the clamping force of a bolt with a nut? What would be the difference in how the fasteners/members would react to a tensile...
  3. mopit_011

    Force on three Bolts holding up a Jet Engine

    My solution was that there would be a force of 0 Newtons on the bolt as the bolt is not moving. But this answer is wrong. Where am I going wrong?
  4. M

    Determine how many bolts are needed to secure a block of steel

    I work in injection molding and I am looking to make some sort of standard for how many bolts are needed to secure what we call a "manifold spacer block". We are constantly battling each other about blocks being under or over secured, and as a manufacturing engineer, I am interested in knowing...
  5. A

    Shear Force on Bolts mounting gearbox to engine

    Hello, I have designed a gearbox that bolts on to a fixed engine and fixed pump. It is completely supported by them. The total mass of the gearbox and the components attaching it to the engine and pump is 7.7kg. Its centre of mass is 0.167m along the x-axis and 0.09m along the z-axis from the...
  6. CynicusRex

    Appropriate tightness of bolts between skateboard and trucks

    As you can see in the pictures below the trucks are attached to the skateboard with four screws nuts and bolts, with a 2~3mm piece of rubber between the truck and the board. I've always wondered if tightening the screws bolts harder, decreases or increases the strength of the 7-layered plywood...
  7. J

    Static Analysis of Bolts on Multiple Surfaces

    I am trying to analyze if the bolts in my design are sufficient to support the load on a shaft. Unfortunately, the bolts are not all located on one face, and though I know how to analyze each face by itself, but I would like to be able to combine them all into one problem. I have attached a...
  8. C

    Bolt Tightening - Torque versus Tension

    Hi guys, Bringing myself back up to speed with bolt tightening, would really appreciate if anyone has some resources or answers to these questions: 1. The proof load for torque tightening, and proof load for tension tightening 2. Main advantages and disadvantages between the two 3. What is...
  9. C

    What force is preventing car wheel bolts from being removed?

    Let's say we want to change a wheel in a car. We want to remove bolts fastening the wheel using this tool: I have also drawn a diagram of the forces in operation: Now, from experience I can say that the point of rotation of the wrench will be the blue point. Now, trying to determine the...
  10. CameronRose

    Shearing when bolts are arranged radially

    Hi folks, I'm currently working on a final year project on the design of a plunger pump. The most recent area I have been studying is the loading on different joints in the pump. For a simplified example I have determined the maximum torque load on the crankshaft from the plungers for the...
  11. S

    Determine the shear stress in the bolts

    Homework Statement Two coaxial shafts are to be connected by a flanged coupling having six 15 mm diameter bolts equally spaced around a 300 mm diameter pitch circle. Determine the shear stress in the bolts when 300 kW is transmitted at 400 revs/min; (i) Assuming the bolts are equally loaded...
  12. E

    Basic Forces & Bolts: Getting Started on Homework

    Homework Statement Homework Equations sum of forces in x and Y = 0 sum of the moments at a point = 0 Ffr = normal force * friction coefficient The Attempt at a Solution Im just trying to make a start, I am struggling to wrap my head around the basics with this question. Do you guys think...
  13. S

    Impact Load Due for Dropped Mass onto Bolt Threads

    Hello, I have an installation tool (which basically consists of a standard long bolt and nut) and a 100 lbs mass object would drop onto it (as if it were a hook) from about 1 - 2 inches. There are many forces to consider and I am looking into that. Since this installation tool will be...
  14. C

    Threaded Bolts in Aluminium - Strength Info Needed

    I'm looking for any information about the typical strength for bolts that are threaded into aluminium. I've tried googling them but I'm having hard time finding information; I've tried looking through machinery's handbook and it doesn't seem to be showing the information for this specifically...
  15. Guest312

    Optimizing Movable Joint Parts for Slider Crank Mechanisms

    I want to make a simple slider crank mechanism. I don't know what type of bolts or whatever is used for movable arms. I've heard online so far that using a carage bolt and nylon lock nut will work, but I bet there's probably other ways to make a movable joint. Something more secure. I'm sure...
  16. Steven Ellet

    How do computers interpret binary code for text?

    If I am too vague, please let me know How do computers read binary? I know that the 1s and 0s represents on and off. if I spell out "hello" in binary using lamps 0=off and 1=on and I take that and try to feed that info to my pc, well I'm going to fail because my pc has no way of handling that...
  17. J

    Will my steel ejection mold bolts shear under sideways load?

    hello. I have a ejection mold (steel) which has a bridge like mount which locates the handling eye bolts outward around hydraulic cylinders. I need to make sure the bolts in the bridge will not shear due to the sideways load when the mold is lifted or flipped 90degrees. Here is the known...
  18. I

    Question on Statics -- San Francisco Bay Bridge Bolts

    Homework Statement http://cisephysics.homestead.com/files/NewSanFranciscoBridge.pdf My question is on this problem. For some reason, I have trouble seeing which direction the force is pushing when it comes to statics. In this case, why is the column pushing up? I thought it would be going down...
  19. B

    Where to Find High-Quality Class 4.6 Bolts?

    Hi all We have been sourcing Class 4.6 bolts of the following specifications : 1. Acceptable fastener standards: ISO4762 (Cap Heads), ISO4014 (Hexagonal Head), etc 2. Mechanical properties: ISO 898-1:2013 especially Table 2 and 3 with impact energy of at least 27 J tested at – 20 degC or...
  20. L

    Designing Bolts for 500kg Machine Component in Trains

    We are working on a machine component structure that weighs around 500 kg.This component is fixed inside the train on top roof using 6 bolts..Now the part is we need to design bolt size and no of bolts under worst condition..The acceleration of train may be taken as 0.3g,where g-accn due to...
  21. D

    Tension on bolts in anchor plate on concrete wall

    Hi. I need help calculated the tension on bolts in an anchor plate. The plate is bolted to a concrete wall with four bolts (see the included image). A bending moment acts on the plate, offset a bit up/down. The bending moment acts from up to down so that the upper two bolts are in tension and...
  22. Y

    Tank of pressurized air to loosen bolts

    Car mechanics use compressed air tools to open bolts. Instead of using an air compressor one can also use a tank of pressurized air. There is an air tank with a volume of 50 L to work with. The pressure of the tank is 50 bars when it is stored indoors at 20 °C. The bolt wrench needs at least 10...
  23. MattRob

    Lightning Bolts / Relativity of Simultaneity

    So, I think most of the folks here are familiar with Einstein's thought experiment that illustrates the relativity of simultaneity by using two lightning bolts and how the light reaches an observer on a moving train; that an observer on the ground observers the strikes simultaneously, but an...
  24. M

    What is the Shear Stress in Bolts for a Given Torque and Separation Distance?

    Homework Statement jan 2012 q3.jpg I've solved everything up to part d). I generally struggle with questions on bolts and I'm really not sure how to tackle this problem. Homework Equations τ = Tr/J, τ = 200MPa, T=1kNm The Attempt at a Solution I worked out the separation of the bolts (I...
  25. sanjay pradhan

    How i determine number of bolts on flange

    how i determine number of bolts on flange
  26. M

    Strength Testing Welded Steel Tubing and Bolts for a Weight Lifting Bench

    I had a piece of box section steel tubing, 400mm long, 5 x 10cm section, 3mm thick. It has a foot welded to the bottom which stabilises it at the floor (this is in red). It is a weight lifting bench. I needed to shorten the length, so I cut it in two and overlapped a join, then fixed it with 3...
  27. S

    How much load is going through the bolts

    Hey guys. Im building a special type of squat rack for my gym, and need some input on the bolts to use. I have used high tensile M16 bolts on all joints, but am not sure if it is enough, hence me joining this forum and asking you guys. Attached is a picture, and Ill explain the lines I've...
  28. H

    How does preloading help reduce stresses in bolts?

    Hi guys: today I learned in class that if you have two members that you wish to joint together, that each of them will experience a force away from each other. A bolt is there to prevent them from moving apart. however, that's the obvious part, what get my confused is that, how exactly...
  29. P

    Why are UNF threads being used in this high temperature Boiler Code application?

    I saw the assembly of a high temperature Boiler Code application the other day. They used nickel and Chrome alloys for the high temperatures. I found the flanges to be particularly interesting. They were using UNF threads, which is not common in boilers, and they were using threaded rod with...
  30. M

    Disk Brake Connections: Finding Torque & Bolt Amounts

    I'm trying to connect a disk from a brake to a shoulder using self locking screws but can't find a formula that would help me to calculate the torque these screws would be subjected to or how many bolts I would need. What do I need to do?
  31. W

    Calculating total stress in bolts that holds an actuator?

    Hi All! I am currently busy working on a new knife gate valve design. I have an actuator with a mass of 200 kg attached at the top of the valve. The bottom plate of the actuator is 28 mm thick and I am going to use this plate directly to fasten the actuator(see attached drawing for plate...
  32. K

    Did I Witness a Moving Train or a Stationary One? The Mystery of Bolts of Light

    Suppose I´m right in the middle of a train and suddenly bright light bolts out of both ends of my train. I swear that I saw both bolts of light at exactly the same time. Later I saw historical evidence of the char marks at the ends of my train. Although my train seemed stationary to me, an...
  33. C

    Calculating Cam Gear Bolt Force: Formulas and Tips for Optimal Performance

    Hi, I'm trying to find some formulas to figure out the force on the bolts of a cam gear.
  34. J

    Number of bolts required for a flanged coupling?

    Hi everyone. This question is giving me a real headache (literally). It should be simple, but I’ve spend probably the last 4-5 hours trying to figure it out. The left side of my brain is redundant. Homework Statement The following specifications are used for the design of a flanged coupling...
  35. W

    Wretched Wrenches and Blustering Bolts

    So I have asked a few wrench questions and bolt questions, now to tie them together (figuratively). Please excuse my variables if they do not match your own. Do I understand that the Ideal Mechanical Advantage of a wrench is like a wheel and axle system where: IMA = radius (wrench) / radius...
  36. A

    How can I effectively brainstorm for FMEA analysis on bolts in a manufactory?

    Hi everyone I am starting on my thesis for university and I would like to please for suggestions. I have topic that belongs to quality assurance and it is FMEA Analysis In The Manufactory Of Bolts. I have done some research on google, picked up some worldwide companies where are producing...
  37. C

    Brake Disc Design- Torque Acting On Wheel Stud Bolts

    Brake Disc Design- Torque Acting On Wheel Stud Bolts I have currently been working on designing a brake disc assembly. The current problem i am having is trying to workout the force acting on each wheel stud. The frictional force of the brake pad is 3.2 KN with an efective radius of...
  38. C

    Brake Disc Design- Torque Acting On Wheel Stud Bolts

    Homework Statement I have currently been working on a group project designing a brake disc assembly. The current problem i am having is trying to workout the force acting on each wheel stud. The frictional force of the brake pad is 3.2 KN with an efective radius of 105MM from the center...
  39. F

    How pressure inside container reacting on bolts.

    Homework Statement I am trying to learn how pressure inside a container reacts on bolts holding the container together. This image shows the probleme. I am interested in how to calculate the forces reacting on the bolts. Homework Equations force=pressure*area area circle=...
  40. Ranger Mike

    Why did all the high-grade flywheel bolts shear on our race car?

    High grade ARP bolts used to attach flywheel to crank shaft..all broke. race car came intoi the pits with engine running and no power to the drive wheels. we pulled off the body panels and could see the rear of the crank shaft. it turned when we turned the front pulley on the crank snout..but...
  41. C

    Using 2 bolts M12 or 4 bolts M6?

    Hi there, I'm not sure that using the same type of 2 bolts M12x1.5 (L=30mm) or 4 bolts M6x1 (L=25mm) & place equidistant in a circle as picture below, which can bear force better & why? Thanks many in advanced! [PLAIN]http://img824.imageshack.us/img824/7971/123ok.jpg
  42. A

    Are Metric and Imperial Bolts Interchangeable?

    Hi guys, i want to ask about bolts, the metric and imperial bolts, are they the same but just one of them is in inches while the other one is in mm? What would a 1/4 inch bolt be equivalent to, a M6? Thanks!
  43. P

    Problem calculating stress from torsion in mounting bolts - PLEASE help.

    Hello all, I need some desperate help. I have a product that is mounted on four corners with 1/4-28 bolts with a shank diameter of .25. The product is mounted to a vibe table and shaken at 20g in each of the three axis. I am currently analyzing the stresses induced in the fasteners in order to...
  44. S

    Shear stress on bolts (in different planes)

    I am trying to understand the behavior of bolt in different plane. My doubt is when shear force acts on bolts in 2 different plane simultaneously, does it share the shear force (F/2) or each bolts experience the total force (F). I am sure that if there is a bolt pattern on the same...
  45. A

    Pacemakers and lightning bolts

    I'm working on a lightning bolt experiment at U of Washington to see how carbon composite materials hold up when hit by lightning. We have as much as a 40 kV 80 kA 50 us arc across a <1cm gap from a copper/tungsten electrode to a plate of carbon composite connected to ground. I know this must...
  46. F

    Calculating resistance between two bolts connected to a metal plate

    Homework Statement Given is a metal plate with two metal bolts attached to it, the attachement is assumed to be idealy conducting. A current I flows between the two bolts. Find a general formula for the Resistance between the two bolts (depending upon: a) the thickness of the plate (delta)...
  47. B

    How Many Bolts Are Needed for PVC Flanges on a Filter Column?

    Hello everyone. I really in dire need of your help as i am not a mechanical engineer, so at this stage i am busy finding out the right design of PVC flanges for a filter column. But the thing is How to choose the right bolts ? i mean how many bolts should i have for my flanges and what...
  48. L

    Help with Allen Head Cap bolts

    Help with Allen Head Cap bolts... Hi, Received today a new headphone amp. It is aluminium construction and uses 4 allen cap bolts at each end to hold the case together. It is all good (was cheap), but the bolts used are clearly low quality and don't look right. I would like to replace them...
  49. A

    Uses of Shoulder Bolts: A Comprehensive Guide

    Hi, Can you please explain where shoulder bolts are used? Specific application?
  50. L

    Exploring the Reach of Tesla Coils - Electric Bolts & Safety

    I watched a home video about the Tesla coil and saw the electric bolts...i thought the guy was standing kinda close to this thing but never got struck. Is there a limit to how far away the bolts of electricity can go from the coil? They looked pretty random.