Tightening the nut stretches the Related Topics . T= Target tighten torque K= Coefficient of friction (nut factor / Slip Factor), always an estimation in this formula D = Bolts nominal diameter P = Clamp Load or Bolt's desired tensile load (generally 75% of yield strength) Above Three factors affect how much tension occurs when a given amount of tightening torque is applied. Bolt torque Torque is the turning force measured in Newton metre (Nm) applied to tighten (turn) the nut on a bolt. The amount of force on a fastener is called as torque. See also this calculator and this table. The most basic way to calculate torque is to multiply the Newtons of force exerted by the meters of distance from the axis. When the nut and bolt are tightened the two plates are clamped together. In a bolted flange, the applied torque generates the axial load in the bolt. article explores how bolt torque should be calculated and applied to seal a flanged connection. K Factor is a torque coefficient between bolt and receptacle. The proof load itself is usually 85% to 95% of a bolt’s yield strength, but the clamp load is significant because it is what ultimately provides the clamping pressure. the breakout torque seen at the bolt head or at the nut of the fastener. Running torque should be included in the values listed in the tables because any torque puts shear load on the bolt. The thread converts the applied Torque into tension in the bolt shank. The first factor is the bolt's diameter. To calculate the true torque for the fastening application, use this formula. Note that columns five and nine use a 1.375 safety factor. Bolts that are fully or partially threaded, with washers and nuts are called as metric bolts. For the past 40 years, when the oil and gas industry thought of bolt lubricant, it focused on disassembly — i.e. TORQUE TIGHTENING ANALYSIS RESULTS Example calculation for a M12 bolt. We will evaluate target bolt torque required for leak-proof tightening. Torque Calculation https://www.tutorialspoint.com/videotutorials/index.htm Lecture By: Mr. Pradeep Kshetrapal, Tutorials Point India Private Limited Torque is the application of force acting at a radial distance and tending to cause rotation; this is also called torque loading. K Factor is a torque coefficient between bolt and receptacle. T = K x D x P. Where: Pitch of cross section of bolt (JIS B1082) * From Max. Torque is the turning force measured in foot-pounds (ft-lb) or inch-pounds (in-lb) applied to tighten (turn) the nut on a bolt. WHAT IS TORQUE? Use the following Torque Calculator for ASTM A193 B7 and ASTM A320 L7 bolting, as specified in API 6A, 16A and 17D for flanges. Torque can be measured during flange assembly with a properly calibrated torque wrench. It’s used to create tension in threaded fasteners. K – constant d – diameter of bolt (m, in) F – axial bolt … First, it’s helpful to understand that torque is a rotational force that is equal to a linear force times the distance … I know there are various ideas from all sorts of engineers out there but it is still nice to hear answers to a question that I personally put forth. Bolted Joint Torque Explanation and Calculation . Torque Calculation. Once the clamp load is determined, finding the correct torque value for a bolt is one simple calculation away. The minor diameter is the smallest diameter of a screw thread. The bolt acts like a spring. It is also the nominal size of the bolt. torque necessary to achieve a % of bolt yield. In a bolted flange, the applied torque generates the axial load in the bolt. In this video (part 2) we look at what it takes to calculate torque. Ultimately at the end of the day, apart from the gasket seating and bolt torque calculations, I would also want to perform a flange leakage calculation. Bolt Torque is the twisting or turning force applied to tighten the nut on a bolt. This torque creates an axial force in the bolt. Bolt Clamping Force vs. Bolt load calculation: Maximum bolting torque is considered to develop 40% to 60% of bolt yield stress. Calculate nut rotation for a given bolt torque Definitions: The major diameter is the largest diameter of a screw thread. 5/16" -18 3/8"-16 1/2"- 13 5/8"-11 3/4"-10 10,000 9,000 8,000 7,000 6,000 5,000 4,000 3,000 2,000 1,000 0 SAE Grade 2 Bolts SAE Grade 5 Bolts SAE Grade 73 SAE Grade 84 Tensile Size Bolt Stress … The first factor is the bolt's diameter. Calculation of Nut Rotation. The bolt acts like a spring. Calculation of the frictional torque adjusting nut – bearing surface M =R: L M M L M R L F d d F d M F 0.075 2 0.15 2 Simplified with dM d: MR 0.075 FL d Note: MR only comes into effect if the adjusting nut is pressing on the bearing surface. F = Target bolt load, N (lb) Example: Let us consider 1’’ bolt of SA193 Gr. They are of two types, metric flange bolts and metric hex bolts. Tightening Torque for Unlubricated Steel Bolts. Various K Factors Various K Factors (A similar table was published … The bolt torque is dependent upon packing cross section, gland bolt diameter, packing style, sealed pressure and the number of bolts. mm These formulae may be used for bolts outside the range of the tables overleaf. The torque values in table V have been calculated as noted in the footnotes, by using formulas from reference 3. It equals the contact force between the clamped plates. Example) σmax=210×(0.2÷0.14)=300 [N/mm 2 ] 7) MAX BOLT PRELOAD - The bolt preload is the amount of tension that is generated in a bolt when the tightening torque is applied. (Also referred to as the root diameter.) Presented below are the results from TORQUE for a M12 Grade 8.8 bolt. It is a function of the materials' frictional characteristics, which are based on surface finish, coatings and so on. Most terms are consistent with the It is a function of the materials' frictional characteristics, which are based on surface finish, coatings and so on. Torque being exerted on the adjusting nut: Tighten: The tightening torque equals the total torque applied minus the prevailing torque. Bolt torque Torque is the turning force measured in Newton metre (Nm) applied to tighten (turn) the nut on a bolt. Bolt Tightening 2 Bolt Tightening 2-1 Various Tightening Methods Various tightening methods 34 2-2 Screw and Torque Relation formula between screw and torque 35 2-3 Torque Coefficient (1) Formula of torque coefficient 36 (2) The torque coefficient is not stable 36 (3) Even when the torque is stable, axial tension may vary 36 The rotation of a bolt (torque) at some point causes it to stretch (tension). It is found that for the clamps under consideration the Equation (15) is not exact and does not give a conservative result for the total friction capacity estimation and Equation (14) gives results much closer to As a reality check if we approximate to a cross sectional area of 7 mm 2 and a load of 1000 N that gives a tensile stress of 140 MPa which is below yield even for low tensile steels.. Tightening torque to preload a bolt Metric thread : M1 M1.2 M1.6 M2 M3 M4 M5 M6 M8 M10 M12 M14 M16 M20 M24 M30 M36 M42 - 3.6 4.6 4.8 5.6 5.8 6.8 8.8 9.8 10.9 12.9 Some flanges can be over-tightened to the point that the ring groove or the flange can be damaged. B7 is required for flange joint material with nut factor of 0.16. We are often asked what torque value should be used with a specific nut/bolt assembly. Bolted joints are often tightened to 75% to 80% of bolt proof load. of axial stress is considered about dispersion of torque coefficient. Example Calculation - Metric Units. The following equation can be used to determine appropriate bolt torque. (These calculations are in metric units, the TORQUE program can also work in units of inches and pounds and work with the unified thread form.) Several factors affect how much tension occurs when a given amount of tightening torque is applied. Size Recommended Torque; Grade 2 Grade 5 Grade 8 18-8 S/S Bronze Brass; Coarse Fine Coarse Fine Coarse Fine Coarse Fine Coarse Fine Coarse Fine #4*-----5.2-4.8-4.3 Bolt Torque. That figure is about right for a low tensile bolt. Bolt Torque Calculator - Calculate required bolt torque; Improvised Torque Wrench - Improvised torque wrench with luggage scale; ISO 724 - Metric Threads - Dimensions of metric threads according ISO 724; Metric Bolt Head and Wrench Size - ANSI/SO, DIN and JIS bolts The magnitude of that rotation is torque (τ), expressed in newton-meters (N∙m). article explores how bolt torque should be calculated and applied to seal a flanged connection. Using a calibrated torque wrench (Manual or Hydraulic Torque Wrench), flange bolt torque can be measured during flange assembly. There's also a rotational version of this formula for 3-dimensional objects that uses the moment of inertia and angular acceleration. A 'prevailing torque' is required just to rotate the nut on the bolt. Metric Bolt Torque Calculator. bolt torque calculation formula excel, This formula is used in some documents for clamps joints friction capacity calculations (for example Reshetov,1974). This is the maximum torque that can be applied to the bolt without stripping the internal threads, using a safety factor of 1.25. Fasteners - Bolts, nuts and threaded rods - torque, tension and loads; Related Documents . 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 Torque Calculator. The calculator below can be used to calculate the torque required to achieve a given axial bolt force or load. to Min. The calculator is generic an can used for imperial and metric units as long as the use of units are consistent. Equation for Flange Bolt Torque Calculation. Accepted formulae relating torque and tension, based on many tests are: M = P x D M = torque lbf.ft 60 P = bolt tension lbf D = bolt dia.ins Or for metric sizes: M = P x D M = torque N.m 5000 P = bolt tension Newtons D = bolt dia. When tightening a fastener with a torque wrench, which is one of the easiest and most common methods, the fastener is considered to be properly tightened once the specified torque is achieved. When using extension adapters and spanners, the torque applied to the fastener is greater than that preset torque setting or the torque value displayed on the tool. 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