# How to torque bolts to spec

How to Determine a Torque Specification

As an example, we can utilize the equation to find the correct torque value for a zinc-plated, heavy structural bolt, in this instance belonging to ASTM A with a ? inch diameter and 10 TPI. As = ?/4 x (3/4in. - /10))? As in? Using this value, the clamp force can now be niceloveme.comon: Cullen Blvd, Houston, , TX. The bolt is stressed up to the proofload value, and if there is no deformation, elongation, or fracture, then the bolt is deemed to have passed. For bolting specifications that do not have a published proofload, it is usually calculated at 92% of minimum yield strength.

The relation between applied torque and axial force - or load - in a bolt can be calculated in this general equation as. Typical Metric and Imperial bolt torques are indicated in the links below:. Metric Bolts - Tightening Torques. US Bolts - How to call nbc news Torques. The calculator below can be used to calculate the torque required to achieve a given axial bolt force or load.

The calculator is generic an can used for imperial and metric units as spce as the use of units are consistent. K - constant. Hoq - axial bolt force or load N, lb f.

The required bolt clamping force for a joint is lbs. The proof load for a M30 metric bolt grad 8. The reduced torque can be calculated. The torque required to achieve this force with a dry bolt is calculated to Nm. By failure the bolt is lubricated and tightened with the same torque Nm. The force acting in the lubricated bolt can be calculated as. T - torque Nm, lb f ft. Add standard and customized parametric components - like flange beams, lumbers, piping, stairs and more - to your Sketchup model with the Engineering ToolBox - SketchUp Extension - enabled for use with the amazing, fun and free SketchUp Make and SketchUp Pro.

We don't collect information from our users. Only emails and answers are saved in our archive. Cookies are only used in the browser to improve user experience. Some of our calculators and applications let you torquf application data to your local computer.

Tag Search en: bolt torque boltts calculator tension. Privacy We don't collect information from our users. Citation This page can be how to finger my girlfriend as Engineering ToolBox, Boolts Torque Calculator.

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Suggested Starting Torque Values

The relation between applied torque and axial force - or load - in a bolt can be calculated in this general equation as. T = K F d (1 - l/) (1) where. T = wrench torque (Nm, lb f ft) K = constant that depends on the bolt material and size. d = nominal bolt diameter (m, ft) F = axial bolt force (N, lb f) l = lubrication factor (%). Nov 14,  · The wrong way, asserts Archer, is to pick a number off a standard engineering table or to rely solely on the classic equation, T = KDP, in which T is the target tightening torque; K is the coefficient of friction, or nut factor; D is the nominal diameter of the bolt; and P is the desired tensile load on the niceloveme.com: John Sprovieri. Values calculated using industry accepted formula T = KDP where T = torque, K = torque coefficient (dimensionless), D = nominal diameter (inches), P = bolt clamp load (lbs). K values: waxed (e.g. pressure wax as supplied on high strength nuts), hot dip galvanized, and plain non-plated bolts (as received)Phone:

Log In. RE: How to measure bolt torque without a torque wrench JStephen, I knew what you meant, but the image that came to mind was somebody patiently scraping the skin of a fish, and applying the results to a cheater pipe RE: How to measure bolt torque without a torque wrench Why can't you just get an extension for your torque wrench??

Having said that, the Turn-of-Nut method is reliable and repeatable. Take the bolt to a "snug tight" condition, meaning full face contact of all surfaced. RE: How to measure bolt torque without a torque wrench Wouldn't the "turn of nut" method also be dependent on the length of the fastener?

As the fastener length grows length through componenets , it would take more turns to produce an equal amount of strain. For loading studs to only 30 to 40 Kpsi, the stretch required would be 0. With 8TPI you get 0. Thus for a 10" stud, you would want 0. RE: How to measure bolt torque without a torque wrench TheTick RE: How to measure bolt torque without a torque wrench I know I'm slightly late on this one, but I stongly suggest that you look at a load indicating bolt, sold under the trade name 'Rotabolt'.

As far as I know, this is about as accurate as you can get. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework. The Eng-Tips staff will check this out and take appropriate action. Click Here to join Eng-Tips and talk with other members! Already a Member? Join your peers on the Internet's largest technical engineering professional community.

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Students Click Here. Related Projects. Home Forums Mechanical Engineers Activities Mechanical engineering general discussion Forum How to measure bolt torque without a torque wrench We need to torque bolts holding teeth in a conveyor drive sprocket, but there is not enough room to fit the head of the torque wrench on the nut the bolt head is head by the tooth casting. I have heard of a method to estimate torque by counting the number of turns after finger tight. How would this work for an M20 bolt that needs to be torqued to ft lb?

First of all, I don't think you mean ft lb on a bolt. Any rule of thumb to estimate this value like counting threads seems hopelessly wrong in my view. The goal when tightening a fastener is to achieve the desired level of prelaod. Using a torque wrench is one method of estimating the preload. In fact, it is one of the least consistent and reliable methods. The turn-of-the-nut method is generally recognized as a better method of preload control then torque.

So, no need to involve torque in the process at all. If the application is sufficiently important, you should test the actual configuration to obtain the relationship between turns from snug and achieved preload. Why not just experiment? Set up a mock assembly, tighten the bolt, and count turns. But tighting to yield is an acceptable practice if using new bolts each tightening. With this method, one should be able to feel yeild and stop pulling on the wrench when proper torque is reached A method used with big studs, where torque is considered too inaccurate is to apply a "pulled-up wrench tight" intial torque about 30 ft-lbs in your case, just needs to be consistant , then using the thread pitch and the modulas of elasticity of the bolt calculate the degrees rotation to stretch the stud.

For bolts I'm familar with, 30Kpsi loading is desired, which is achived with 0. Then with an 8-TPI nut, one will get about 0. Measuring flats is common instead of degrees. Assuming 22 mm hole size, 28 mm screw head outer contact diameter, 0.

To achieve kN via an angle tightening specification, you need to know the compliances of the joint and screw. Then, you can calculate the required axial deflection to produce the desired preload. Thus, you need dimensions and materials properties for all joint members.

JStephen, I knew what you meant, but the image that came to mind was somebody patiently scraping the skin of a fish, and applying the results to a cheater pipe Why can't you just get an extension for your torque wrench?? Wouldn't the "turn of nut" method also be dependent on the length of the fastener? Yes, the longer the stud, the more turn to achieve the same "torque". Regards, MB. I know I'm slightly late on this one, but I stongly suggest that you look at a load indicating bolt, sold under the trade name 'Rotabolt'.

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Close Box. Posting Guidelines Promoting, selling, recruiting, coursework and thesis posting is forbidden. Home Forums Mechanical Engineers Activities Mechanical engineering general discussion Forum How to measure bolt torque without a torque wrench 10 thread Forum. How to measure bolt torque without a torque wrench How to measure bolt torque without a torque wrench We need to torque bolts holding teeth in a conveyor drive sprocket, but there is not enough room to fit the head of the torque wrench on the nut the bolt head is head by the tooth casting.

RE: How to measure bolt torque without a torque wrench First of all, I don't think you mean ft lb on a bolt. RE: How to measure bolt torque without a torque wrench The goal when tightening a fastener is to achieve the desired level of prelaod.

RE: How to measure bolt torque without a torque wrench Why not just experiment? RE: How to measure bolt torque without a torque wrench A long cheater pipe and a fish scale should do the job.

RE: How to measure bolt torque without a torque wrench Assuming 22 mm hole size, 28 mm screw head outer contact diameter, 0. Resources From functional prototypes, tools and fixtures to end-use parts, the 3D printing industry is transforming many other industries and processes.

Download Now This whitepaper reviews the results of performance testing conducted with Ansys Fluent when making use of the Intel MKL sparse LDU smoother, and it explains how the improved performance results were accomplished.

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