Do not use these values if a different torque value or tightening procedure is given for specific application. Lubricated refers to fasteners in the as received condition, which is normally a light preservative oil coating on unplated fasteners and no oil coating on plated fasteners. The torque values given in the table are simply an equivalent to hand tightening using a podger spanner. Without the proper analytical tools and information, specifying the correct torque can be. This is due to its simplicity and its widespread understanding by all engineers. Tests with bolts, nuts, lock nuts, inserts and locking inserts are provided to assess this approach, and the results show. Approximate values for metric co threads vdi 2230 bossard group bolt torque chart pdf zenam vtngcf org iso bolt torque chart zenam vtngcf org approximate values for metric co threads vdi 2230 bossard group. The final tightening sequence is achieved smoothly and slowly. Clampload is only a estimated number, there maybe situations where the engineer calls for the bolts to be tensioned to a different value.
Measured frfs show that there is no effect of bolt preload above 10 nm tightening torque figure 6. Modal analysis has been performed for increasing bolt tightening torque levels, from 0 to 25 nm the nominal value in steps of 5 nm. Torque control method bolt tightening is controlled by specific torque value. These formulae may be used for bolts outside the range of the tables overleaf. Only applicable to shaft screws with metric standard and fine threads acc. Heating method tightening is controlled by the variation of the elongation before and. Bolt size mm, pitch mm, bolt hex mm, strength grade nm. Apply suitable axial tension it is best to do axial tension control for tightening screw, but actually it is difficult to measure. For torque controlled tightening, achieving the right preload is dependent upon the correct tightening torque being specified. This approach uses both tightening torque and removal torque measurements. Preload and tightening torques for stainless steel fasteners coarse metric threads.
Shobergs efforts it is now gaining wide acceptance in other industries, such as automotive, in critical application like engine head bolts and connecting rod bolts. Follow any special instructions or multistep directions carefully to assure correct final torque. Pocket guide to tightening technique this booklet provides an introduction to the technique of using threaded fasteners for assembling components, the application of power tools for the assembly and the influence of tool selection on the quality of the joint. The material is en 5052 t5, which is an aluminium alloy which has rp0,2 on 60 mpa, which isnt that much. If an air wrench is used make sure the pressure is set to the minimum. Standard, and updated referenced australian standards. Bolt tightening table table 14 table 15 figure 21 1.
Custom bolt tightening solutions we aim to provide special tensioner solutions within one week of receiving the enquiry. Technical data suggested tightening torque1 values to produce corresponding bolt clamping loads notes. Coefficient 44 45 rs 3 tohnichi torque handbook vol. It should be noted that these figures are based on the first tightening of single assemblies in isolation. There r tabels for 8,8 screws, but the strength of the alloy is only 60 mpa so i wonder if i should use less. Torquing tightening flanged joints in which torsional loads are applied to the bolts causing the bolt to stretch, due to the relative movement between the nut threads. Torque control and torqueangle control tightening methods using torque to indirectly control a bolt s preload is by far the most popular controlled tightening method. This work reveals preload is proportional to tightening torque minus removal torque and that taking this torque difference subtracts out friction. Lubricated bolts and reduced torque lubrication effect on bolt tension and torque.
Surface condition torque adjustment factors plain steel, as supplied x 1. Boltmasters pty ltd recommended assembly torques author. Tightening the large diameter anchor bolts of sign, signal. Metric bolts tightening torques typical maximum recommended thightening torques for metric bolts. Tightening torque hex bolts the tightening torque values given in the above table serve only as a guide. Use specified bolts and nuts, tightening them to the torques specified in this. The sci recommends that generally, torque on ordinary bolts need not be checked. Values calculated using industry accepted formula t kdp where t torque, k torque coefficient dimensionless, d nominal diameter inches, p bolt clamp load, lb. The tightening device and bolts are specially made.
The torque turn tightening method has been the required procedure for tightening structural bolts for many years. Torque control and torqueangle control tightening methods. Screw tightening is carried out in order to stop objects from moving to fix them. Standard maintenance practice dictates that mechanics add this value to the specified torque. Always replace shear bolts with identical property class. There may be different specifications for different size bolts, bolts in different positions, tightening bolts in several stages, or a cold engine vs. Perform one final pass on each bolt working clockwise from bolt 1, at the full final torque. To view the full content, you will need to purchase the standard by clicking on the buy button. Tightening torque for stainless steel screws please use in heatedup condition the half of the values shown. Technical data proper bolt axial tightening force and.
The purpose of tightening screws is to fix one object to another object. One of the central problems of using threaded fasteners for. Suggested tightening torque1 values to produce corresponding. Fasteners the torquing of stainless steel fasteners your guarantee of quality industrial fasteners. Standard manufacturing practices for the installation and tightening of fasteners shall apply to all fasteners which. Tightening torque values are calculated from the formula t kdp, where t tightening torque, lbin k. Metric bolts head and wrench sizes ansiso, din and jis bolts. An bolt torque for oil free cadmium plated steel nuts and bolts inch. Tightening test torque these sizes are not included in din iso 272 note. Metric bolts minimum ultimate tensile and proof loads minimum ultimate tensile and proof loads for metric bolts with coarse or fine threads.
Metric bolts tightening torques engineering toolbox. The torque, or the moment of force, can be measured either dynamically, when the screw is tightened, or statically, by checking the torque with a torque wrench after tightening. Recommended assembly torques steelmasters bolts, nuts. Increase the torque to full torque following the pattern shown above. Then hand tighten till they are snug against the flanges. Tightening torque chart for sae metric bolts wrench free 6 sample bolt torque chart templates in pdf suggested tightening torque values fan disc corporation approximate values for metric co threads vdi 2230 bossard group. Jan 10, 2016 start the tightening procedure by lubricating the nuts and bolts. There are several ways of securing parts and components to. Tightening torque tightening torque tightening torque tightening torque the torque values can only be achieved if nut or tapped hole has a proof load greater than or equal to the bolt s minimum ultimate tensile strength.
Tightening torques for metric bolts of yield strength sy metrique diameter mm 6 8 10 12 14 16 18 20 22 24 27 30 33 36 39 42 45 48 52 56 60 64 68 m6 m8 m10 m12 m14 m16 m18 m20 m22 m24 m27 m30 m33 m36 m39 m42 m45 m48 m52 m56 m60 m64 m68. The anchoring bolts have not been changed from the nominal value. For critical applications, as determined by the engineering project, either the recommended torque or a torque that is unique to the application shall be clearly identified and specified on the engineering documentation. The bolts is 8,8 what tightening torque should i use. If lubrication is to be applied to the nut bolt,multiply the recommended torque by the appropriate factor shown in the table on page 7. Tightening torque for stainless steel screws please use in. Start the tightening procedure by lubricating the nuts and bolts.
Torque has been converted into ftlbs by dividing the result of the formula by 12. Underover tightening of fasteners can result in costly equipment failure or personal injury. Improvised torque wrench improvised torque wrench with luggage scale iso 724 metric threads dimensions of metric threads according iso 724 lubricated bolts and reduced torque lubrication effect on bolt tension and torque. Stainless steel fasteners preload and tightening torques. Pocket guide to tightening technique this booklet provides an introduction to the technique of using threaded fasteners for assembling components, the ap. Tightening torque chart for metric bolts hobbiesxstyle. Increase the torque to twothirds following the pattern shown above. Recommended maximum bolt loads and torque values metric coarsethreads 3. Jan 24, 2018 tightening torque chart for metric bolts by reza 24 jan, 2018 leave a comment chart for sae metric bolts wrench sample bolt torque chart templates in pdf suggested tightening torque values metric co threads vdi 2230. If torque values are required, then the values shown in the above table may be used. These formulae may be used for bolts outside the range of the tables, m torque lbf. Shear bolts are designed to fail under predetermined loads.
As mentioned above, the tightening torque is for practical reasons the criteria normally used to specify the prestress in the screw. Qinitial tightening force and tightening torque a b technical data proper bolt axial tightening force and proper tightening torque technical data strength of bolts, screw plugs and dowel pins 3549 3550 dd 35493550 10. Torque specifications are shown either as an exact figure, or a specific range. Ffmaxfu to adopt % of the minimum required tightening torque, the level that prevent loosening, as the tightening torque. To adopt 70 % of the breaking torque as the tightening torque for screw joints. Breakout torque when loosening bolts a torque value higher than the tightening torque is. Reference values for tightening torque nordlock washers wedgelocking system. Alternatively, use the torquetension calculator on the norbar website which enables fastener and friction conditions to be modified with ease. Graduate theses and dissertations iowa state university capstones, theses and dissertations 2018 tightening the large diameter anchor bolts of sign. Tightening torque tightening torque tightening torque tightening torque bolt clamping force lbs. Iso metric hexagon bolts and screws products grades a and b. Custom bolt tightening solutions standard product bolt tightening solutions we are very aware that there are many diverse and specialised types of bolted joints being used throughout the industrialised world. Clamp loads estimated as 75% of proof load for specified bolts.
Ratio between measuring torque and tightening torque approximate value obtained by experiment table 31. And grade g flange nuts lock nut standards from ifi100 requirements. Extreme caution should be used when using a formula for torquetension relationships. I have an aluminium detail with some helicoil holes m6, m8, m10 and m12. If lubrication is to be applied to the nutbolt,multiply the recommended torque by the appropriate factor shown in the table on page 7. When tightening, always use the correct sequential bolt order for the flange. The importance of tightening torque most engineers already know the importance of a high preload in maintaining joint integrity. T the purpose of tightening screws is to fix one object to another object. Torque diameter threads per inch tpi lbf lbft 14 20 736 3.