By over-tightening the bolt, one may exceed the proof load of the bolt. other bolting torque tables. The total tensile stress felt by the bolt is: S t = P t /2A + ((P t /2A) 2 - (tr/J) 2) 0.5. clamping force can also cause severe problems. Clamp load is also known as preload or initial load in tension on bolt… lb-in. The answer is: Yes and yes. Most company has their Flange bolt torque tightening procedure that used during construction and operation of the plant. Several factors affect how much tension occurs when a given amount of tightening torque is applied. Google use cookies for serving our ads and handling visitor statistics. ; K = torque-friction coefficient; D = nominal bolt diameter, in. We will evaluate target bolt torque required for leak-proof tightening. The formula that expresses the relationship between the load in a bolt and applied torque is: T = K F d K is the coefficient of friction. Torque Why do we tighten screws? T The purpose of tightening screws is to fix one object to another object. You need to provide all the information in this formula (except, of course, for T, which is the torque that you are looking for). Your coefficient will depend on the material of your bolt/nut, the type of lubrication (or, rarely, the lack of lubrication) and the size of the bolt. A mistake in this calculation could cost tens of thousands of dollars, never mind the time and hassle of replacing broken equipment. Typical Metric and Imperial bolt torques are indicated in the links below: Manufacturing data should always be checked before use. We don't save this data. The following design resources are for design screws and bolts for the proper torque, stress, strain, preload and other engineering critical design parameters. If you have questions about how to calculate the tightening torque of bolts for your application, reach out to us at Ultra Torq. Sample calculation: Assuming: An adjusting nut MRR 50x1.5 (2 gibs with M6) is used to clamp a spindle bearing. The Bolt Torque & Preload calculator can be used to calculate the torque required to achieve the desired preload on a bolted joint. This calculator can be used to calculate the force acting in a bolt. As per indian standard, calculation use to calculate tightening torque for all classed bolt, 1 can be rearranged to express bolt force as, F = T / (K d (1 - l / 100))                      (1a). Load is the clamping force of the specific grade of bolt that has been determined to “hold the joint together” for the optimal design of that bolt. It is NOT something you should blindly use. This is the most widely used method. The rotation of a bolt (torque) at some point causes it to stretch (tension). This field is for validation purposes and should be left unchanged. In a bolted flange, the applied torque generates the axial load in the bolt.The bolt acts like a spring.Tightening the nut stretches the bolt, which increases the load on the gas ket.The axial load in the bolt … Note that μ and μcare not necessarily equal, althou… See the reference section for details on … Please read AddThis Privacy for more information. COVID-19 UPDATE The health and safety of our clients and employees is priority and we are taking all steps required to ensure safe conditions for all. Clamp load is also known as preload or initial load in tension on bolt. Method based on breaking torque (Determination of upper limit) To adopt 70% of the breaking torque as the tightening torque for screw joints. The proof load for a M30 metric bolt grad 8.8 is 337000 N. The torque required to achieve this force with a dry bolt is calculated to 2022 Nm. Tightening and loosening torque of the adjusting nut: Tighten: FE = … ... Reference literature: "Theory and calculation of threaded fasteners" Akira Yamamoto (Yokendo Co., Ltd.) The force acting in the lubricated bolt can be calculated as, Flubricated = (2022 Nm) / (0.2 (0.03 m) (1 - (40%) / (100%))). There are numerous "real world" complications. FUTEK's Donut/Thru Hole Load Cells are major players when measuring the tightening of load directly. Some flanges can be over-tightened to the point that the ring groove or the flange can be damaged. The torque required for a 3/4" dry steel bolt with 0% lubrication to achieve this tension can be calculated as, Tdry = (0.2) (20000 lb) (0.75 in) (1/12 ft/in) (1 - (0%) / (100%)), The proof load for a M30 metric bolt grad 8.8 is 337000 N. The torque required to achieve this tension with a dry bolt with 0% lubrication can be calculated as, Tdry = (0.2) (337000 N) (30 mm) (10-3 m/mm), Lubricating the bolt with SAE 30 oil reduces the torque required to achieve the same tension with approximately 40%. By failure the bolt is lubricated and tightened with the same torque 2022 Nm. Torque is only an indirect indication of tension. A popular formula for quick bolt torque calculations is T = KFd, where T denotes torque, F denotes axial load, d denotes bolt diameter, and K(torque coefficient) is a calculated value from the formula: as given in reference 4 (p. 378) where The commonly assumed value for K is 0.2, but this value should not be used blindly. Tightening torque values are calculated from the formula T = KDP, where T = tightening torque, lb-in. of bolt/nut assemblies and for the calculation of torque specifications, which include the case where the fasteners have prevailing torque KEYWORDS: fastener torque, prevailing torque, torque calculation, head finish, thread finish Nomenclature The following is a list of the nomenclature used. In your calculations you should also remember that torque wrenches are not perfectly accurate. in; and P = bolt clamp load developed by tightening. Bolt tightening an overview bolt tightening an overview calculate torque metric co thre vdi 2230 the 5th edition of awwa m11 pipe design Suggested Tightening Torque Values Fan Disc CorporationProper Bolt Torque Zero S IncBolt Torque ChartBolt Torque ChartBolt Torque ChartRoximate Values For Metric Co Thre Vdi 2230 Bossard GroupIs There A Rule Of Thumb… Read More » Confi rmation of the present tightening torque To establish the present tightening torque and confi rm it. Please read Google Privacy & Terms for more information about how you can control adserving and the information collected. The required bolt clamping force for a joint is 20000 lbs. Typical values for K with mild-steel bolts in range 1/4" to 1": Note! (See P.35 Figure 2-8) 2. B7 is required for flange joint material with nut factor of 0.16. 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