Bolt Stretch Due To Torque

bottom alternator bolt 10x160mm. To 51 prevent this condition, the bolt’s pre-load must be greater. d - diameter of bolt (m, in) F - axial bolt force or load (N, lb) torque reduction due to lubrication (%). The preload developed in a bolt is due to the applied torque and is a function of the bolt diameter, the geometry of the threads, and the coefficients of friction that exist in the. in the fast lane. the bolt will stretch too much, and weaken. This will ensure availability of information when required. 0064" NOTES: OF ALL ROD FAILURES ARE DUE TO ONE OR MORE OF THE FOLLOWING: 1. in other words, when you torque down a classic head bolt to the specified torque wrench reading, you are trying to stretch the bolt to a point just under the point at which the bolt will permanently stretch out of length. Hi all, My California spec 1999 Camry's engine has basically went bust due to ringland failure. A Toyota dealer mechanic friend did find a rebuilt one in AZ, but due to life circumstances. a stretch gauge printed on the back of the pattern envelope. * Steel made bolt to solve the problem of chip, insufficient torque,. Some engines just don't have enough space to utilize a typical bolt stretch gauge. I've used torque values for years on many engines both street and race and never lost a lower end I put together. Like Jerry stated, different grade bolts, get different torques to stretch the bolt. Getting the to the precise yield zone (for maximum clamping force) is accomplished by tightening bolts to a certain torque spec, then turning the bolts an additional number of degrees. A stud with oil tightened to a dry torque value could be stretched to or close to failure. How are they different? Can they be reused or do they need to be replaced? I would like to clarify some issues regarding these types of bolts now commonly in use in the automotive industry. Like I do with every engine, I torqued the bolts to the specified amount (50lbs) using my Snap-On torque wrench and ARP assembly lube on the threads*. Bolts are normally tightened by applying torque to the head or nut, which causes bolt to stretch. Torque both bolts to an indicated 25-30 ft-lbs to ensure a small amount of preload. Yeah, ten longs 16 shorts. When you tighten a fastener to a torque value the engineer providing the torque value was trying to achieve a specified stretch of the bolt to deliver the calculated clamping force needed to overcome operating loads without subjecting the fastener to fatigue. The technique suffers from inaccuracy due to inconsistent or uncalibrated friction between the fastener and its mating hole. These factors in-clude bolt diameter, bolt grade (strength), and friction. When a bolt is tightened the shank sustains a direct stress, due to the elongation strain, together with a torsional stress, due to the torque acting on the threads. 17 gearing and 105 kW (140 HP) peak. Without a doubt, bolt stretch is the only truly accurate way to establish proper bolt preload. In addition, a proper bolt torque value can be inconsistent from fastener-to-fastener due to several factors including variations in material, coatings, surface finishes, fit tolerances, installation method, etc. • A note about torque to yield or “stretch” bolts: Many bolts will have a torque specification listed in the format - xx Nm+xx degrees (xx Ft-lbs+xx degrees). Many engines today use "stretch to yeild" head bolts. A lot of fasteners on the front suspension are torque-to-yield, including the front subframe bolts. pressure-surge, pipe bending due to soil settlement, etc. Choosing the right head stud A common misconception with fasteners is the more torque you can apply, the less likely it will be for joint separation to occur (lifting a cylinder head). You can see the additional torque stretching the bolt beyond its elastic limit and as such it gets thinner around the middle, or “necks”. The difficulty with the application of torque is there are multiple variables that can affect how much of the applied torque is used to overcome friction and how much actually stretches the bolt. (Bolts with Specification: Torque plus Angle). Cylinder head bolts are responsible for holding the cylinder head to the engine block. Lubricated Bolts and Reduced Torque - Lubrication effect on bolt tension and torque; Metric Bolts - Head and Wrench Sizes - ANSI/SO, DIN and JIS bolts; Metric Bolts - Minimum Ultimate Tensile and Proof Loads - Minimum ultimate tensile and proof loads for metric bolts with coarse or fine threads; Metric Steel Bolts - Grades and Property Classes. * The prices listed on this website are for estimating purposes only. I can see less of a chance for this happening with an aluminum block. Install vanos oil hose with bolt and 2 new washers (19mm combo wrench). You can buy a $30 rotor at AutoZone for your mini van, not so for your F-car model. The 1st stretch was a used bolt, but the second was a new bolt. "to tight a bolt up to 200n/m without a torque wrench", shanemcconn has rightly answered this part. When torque is applied to a bolt, the torque spec is designed to stretch the fastener to just short of its yield point. Torque to yield bolts. Torque both bolts to an indicated 25-30 ft-lbs to ensure a small amount of preload. The technique suffers from inaccuracy due to inconsistent or uncalibrated friction between the fastener and its mating hole. There should be a dimension for the old bolt length, if they are longer than that they are stretched and need to be replaced. " If nut is overtightened enough to stretch the bolt, the nut and bolt both must be replaced. to gas tank and premium gas due to rough. The torque angle method can be accurate - but only if each individual application has been previously calibrated by direct measurement of bolt stretch. As I see it if you torque the fastenings to the correct values for the bolt size and material, you stand a good chance of crushing the substrate. 006" stretch, or 50lbs if you don't have stretch gauge. TECHNICAL FIELD. Remember bolt stretch is how we get maximum clamping load. If the clamping force is too low, the fasteners can work loose due to vibration or movement between the. External/Internal Loads: P = External axial load applied to joint at bolt location due to application. Ordinarily, the torque applied should not be outside of the 40-60% of minimum yield range. The coefficient of friction of Loctite is similar to a light oil but I wouldn't generally use thread lockers on rod bolts. What holds nut/bolt assembly is the clamping load as a result of fastener’s stretch. As long as the bolt is not stressed beyond its proof load (the maximum load a bolt can withstand and still behave in an elastic manner), it will return to its original length once the torque is relieved. How are they different? Can they be reused or do they need to be replaced? I would like to clarify some issues regarding these types of bolts now commonly in use in the automotive industry. Torque-to-yield (TTY) head bolts should not be reused. Loosen, tighten to full torque, 6 times to all the cylinder head nuts are 22 foot pounds. To get the final torque AND stretch on the bolt, you tighten the bolt a given number of degrees of rotation. The amount of the tension created in the bolt is. In the past 12 months I have done head gaskets on 3 other 99-2001 Altima's with zero issues for other people. An impact wrench is the best solution for use in tight angles where there is no space left to apply the required amount of torque easily. Use of a stretch gauge to measure the bolt stretch and thus directly measure the clamping force rather than infer it from torque is recommended and normal practice in race engine assembly and it is what I use but in its absence make sure you torque to the Lotus recommended values for the 125E rods and bolts. Self-locking nuts use either a pre-installed plastic insert or a chemical substance applied to the threads that, when initially tightened down, spreads in between the threads to create a more stable adhesive bond than the metal-to-metal connection of an ordinary nut and bolt. PRELOAD (TORQUE) RECOMMENDATIONS 8. “Carrillo and every other quality rod. Regardless of the other factors, and no matter how much actual torque it takes to stretch the fastener to the correct length, it’s not properly torqued until it’s properly stretched. Careful inspection of all components must be done prior to assembly and any components showing the above conditions should be repaired or replaced. To use with the 4-Leaf Double-Eye Spring for 3,500 Pound Trailer Axles # SP-210275 I recommend the U-Bolt Kit # APUBR-1. A torque wrench indirectly measures bolt tension. Key benefits:. The problem is, the knuckle becomes the sacrificial lamb with use such as frequent pad changes. Observe and test system operation, using gauges and instruments. to gas tank and premium gas due to rough. I purchased a rod bolt stretch gauge but could never get comfortable with the procedure so I went back to using the torque spec. Oiled threads will decrease the friction in threads to the point where the preload on the bolt will be practically twice as high as if the threads were dry. While it may seem counterintuitive, bolt stretch is desired in a sealing system as it can help maintain the seal. like vims, you start with your applied load, determine the preload you need, then determine the bolt you need. The specification of torque at assembly allows for the stretch and so creates a constant load on the mounting pad. For these reasons, it is not practical to provide a single bolt torque chart or formula that is accurate for all situations. The proper way to tighten the wheel is to use a torque wrench to torque every lug nut to its recommended torque when the car is on the floor. It is a function of the materials' frictional characteristics, which are based on surface finish. More Great 14-Bolt Articles. One at a time, torque each M6 bolt to 120 in-lbs with red Loctite. Rarely being affected by range anxiety due to the 238-mile range, the Bolt has met about 99% of my daily driving needs. Torque-to-yield bolts are intended for one-time use only, and must be replaced to ensure proper clamping due to the bolts ability to stretch for tightening. 0070" 95 If recommended bolt stretch is only achieved by applying torque that is outside of the recommended torque range, there is a problem either with the fastener, the bolt threads, the application of the lube, or the torque wrench. If you do employ the torque angle method, it's best to begin calibrating rotation from some small measured torque rather than the first point of contact with the work face. This would seem to indicate that your bolt is NOT stretch. Most of my CZ's use a torque between 18-24 in/lbs on the screws. Torque application increases tension in the fastener and clamping force between components. Remember the lug bolt will "stretch" over time too. To get the final torque AND stretch on the bolt, you tighten the bolt a given number of degrees of rotation. - rather than the first point of contact with the work face. Torque Bolts 1-10 Again 90-100 ft/lbs 115-125 ft/lbs Torque Bolts 19-22 27-37 ft/lbs 27-37 ft/lbs It’s important to note that if the higher torque value is used on the “6” dash bolts, they may yield (stretch) and lose their clamping ability. This bolt holds the timing pulleys and the fan/alternator belt pulley in place. I just did it whenever I had the valve cover off it it had been 6 months or more. Then we "stretch" the speed corresponding to torque until this peak power is achieved. Torque control method Bolt tightening is controlled by specific torque value. Developments in Construction Bolting and, is all the torque worth the effort? The use of construction bolt assemblies in terms of the new standard EN14399 has been underway for the best part of two years now. Rod bolt, re-usable non stretch type for 1980-85 Vanagon. Stretching the rod bolts is another way of torquing the rod bolts but in a more precise way. The torque values in table V have been calculated as noted in the footnotes, by using formulas from reference 3. The coefficient of friction of Loctite is similar to a light oil but I wouldn't generally use thread lockers on rod bolts. Some bolt info but as Beaner said the fastener topic can get pretty deep. (A similar table was published in Product Engineering by Arthur Korn around 1944. The "no retorque required" head gasket means you don't have to torque it, drive 50 miles or so, then retorque it. The nuts or bolts you are working with, though they are steel or metal, are designed to stretch when tightened. Fasteners 101 - Torque Setting. Remember torquing is overcoming friction. Every fastener has a torque. increments and then tighten 60 degrees,” which will preload the bolt and then stretch it into its plastic range. I just did all the brakes on my son's 2007 Camry and it was pretty easy due to the info being so readily available as well as plenty of YouTube videos. Tray has work lights at the back on the hurdle. In reality, there will be some loss of engagement due to the chamfering around the threaded hole in the nut. Looking at the P/S pump and bracket, there is an upper bolt that is used to mount the P/S. To get the final torque AND stretch on the bolt, you tighten the bolt a given number of degrees of rotation. With less friction (wet threads), the bolt will stretch more before a torque wench will click. I've been torquing it to 90 foot lbs and this last time I reinstalled it with blue loctite and just saw its loose again after a couple of thousand miles. The factory bolt torque figure is a bit high but appropriate for an M14 x 2 bolt/thread in order to impart the proper amount of stretch, resulting in the clamping force that Ford engineers wanted. Since I was in no rush, I gave it 48 hours before I did any further work on the engine. The head expansion will add to the preload on the bolt once the engine is up to temp. Torque-to-yield (TTY) head bolts should not be reused. Torque specs are 15 lb-ft +/- 1 lb-ft for the driven pulley screw at final assembly - step 1. If the bolt is undercut, it will have a different TORQUE value than a non undercut bolt. Following the manufacturers recommended torque sequence tighten the nuts in three equal steps to 125 ft lbs. com • Due to the nature of performance applications, ZRP products are sold without any express warranty or implied warranty. R Model Honing Plate Instructions Tips For Best Results Using A BHJ R Model Honing Plate 1. Lower the axle so it is supported by the straps. The amount of preload is critical…too much and the bolt may exceed its elastic limit (stretch), too little and the bolt maybe subject to alternating forces and fatigue (very common). The cost of a new set of torque to yield bolts is well justified when compared to the costs of having to repair an engine for the second time because of insufficient clamping load due to bolt fatigue. Today more than 1,600 gas and steam turbines worldwide use the ITH Stretch-Method - the leading procedure to tighten and loosen bolted joints in turbine construction. stretch stretch has nothing to do with rod manufacturer and everything to do with the torque wrench, lubrication and the process. High-Strength Carbon Steel Bolt Failures due to Hydrogen Embrittlement (HE) A bolt, or threaded mechanical fastener, is used to transmit its induced tension to components to be connected so that they can react reliably without failure under the imposed loads. gaskets and stretch design of the. 0070" 95 If recommended bolt stretch is only achieved by applying torque that is outside of the recommended torque range, there is a problem either with the fastener, the bolt threads, the application of the lube, or the torque wrench. make certain you have enough clearance around brake, fuel, and electrical lines, etc. Torque meter can be used to measure bolt tension. Torque control method Bolt tightening is controlled by specific torque value. Torque is simply a twisting force, index number, it does not equal load. If a bolt is installed without Tech Tip - THE IMPORTANCE OF PROPER ROD BOLT STRETCH/TORQUE - Offshoreonly. Torque Value WI 30 wt. ARP Head Studs, Main Studs, Rod Bolts Torque and Stretch Specs By admin on November 19, 2010 in Technical Articles This is information that you can never find when you need it so here is a table for the ARP Head Studs, Main Studs, and Rod Bolts Torque Specifcations and Stretch Specs. This is illustrated in the piechart shown above. - rather than the first point of contact with the work face. Stretch & Stress the stud / bolt by tightening multy clamping screws. Or sign in with one of these services. Measure the bolt length, install, torque to whatever torque value specified to take the bolt to 90% yield, untorque the the fastener and measure. Properly setting the torque on a nut or bolt requires you to use a torque wrench. Use the dry wheel lug torque values specified in the vehicle's owner's manual, shop manual or obtained from the vehicle dealer/service provider. Note: Take care not to stretch the brakelines. , shearing or popping off of the bolt head). The knowledge of what makes an engine truly move a rider runs deep at The Motor Company, and it’s been put to particular good use to power the Softail family. Running torque should be included in the values listed in the tables because any torque puts shear load on the bolt. The Subaru 2. Even if you're torquing a single bolt to 90% yield at ambient condition, you can yield it. MBR Main Bolt and Stud Torque. This program provides 15 individual tools that are of common use by structural engineers including: Steel Shape Properties, Section Property Calculator, Natural Frequency Calculator, Bolt Loads and Dimensions, Unit Conversions, Wire and Sheet Metal Gauge, Friction Coefficients, Thermal Expansion, Ma. All Molnar rods are finished in the United States at the Molnar Technologies shop in. I wont use the new arp stuff, I tried it twice and it just galled under the head of the rod bolt both time. Especially with stainless, its best to err on the side of less torque, than more. Look at the catalogue for L19, if you can't find it then go to the standard settings for ARP 220,000psi bolt 3/8th and whatever pitch it is, if you're not happy with that then read the instructions that came with the rods, if you don't have the instructions and don't have a listed torque, then use a stretch gauge. HOW ARE BOLT TORQUE AND TENSION RELATED? Torque is a method of creating tension in the bolt by stretching it. Pretension is often adjusted by applying torque to the bolt, screw, or nut. For torque controlled tightening whether the nut is tightened and the bolt head held, or the bolt head tightened and the nut held, can be of importance. The stretch of a bolt or metal rod loaded in tension is calculated by use of the following equation. This program provides 15 individual tools that are of common use by structural engineers including: Steel Shape Properties, Section Property Calculator, Natural Frequency Calculator, Bolt Loads and Dimensions, Unit Conversions, Wire and Sheet Metal Gauge, Friction Coefficients, Thermal Expansion, Ma. If a bolt is not coming up to normal torque or is not holding a reading, it means trouble. Torque is the stretching of the bolt and platen threads to maximize the strength of the fastener, or mold clamp. Observe and test system operation, using gauges and instruments. Do you set the gauge To zero and then torque with gauge removed or gauge in place and use a box end wrench. Principally this is due to two sets of technologies existing side by side and often in the same engine. A tightened body tightening force stabilization agent capable of minimizing a variation in torque coefficient suitable for controlling a tightened body tightening force by a torque method, comprising, as an active ingredient, a polymer of unsaturated chain hydrocarbon with a carbon quantity of four; a method for stabilization of tightened body tightening force, comprising the steps of applying. This is due partly or mainly to the fact that the bolt is loaded in tension and the nut is loaded in compression. ARP ULTRA-TORQUE FASTENER ASSEMBLY LUBRICANT that is provided with each kit as opposed to motor oil. In truth, I think the 6-speed automatic, which uses a hybrid torque converter and clutch pack system to mimic a dual-clutch, is actually better matched to the powertrain. You may reach that amount of stretch sooner without lubrication due to friction, but thats still the amount that the bolt is rated to work. spotfaced the cap then switched back to my CMD and the same bolt stretched right up like normal. The flange. Unlike torque control method almost all of the input work is used to create tension in the bolt and losses due to friction are reduced to zero. The main reason motors blow a head gasket is warping of the head. See Torque Force Design Equations webpage and torque chart page for recommended fastener torque and equation data. When using the torque angle method, it is best to begin rotation from some small measured torque - no more than ten lb. With a stretch gauge over both ends of the bolt it is difficult to find a 12 sided wrench that can turn the bolt head to the stretch needed without it wanting to slip off or not get in the way of the stretch gauge. Looking at the P/S pump and bracket, there is an upper bolt that is used to mount the P/S. Typical bolts can be an issue when you use them on aluminum heads and with a gasket that doesn’t relax, like an MLS gasket. In spite of this advantage, the. Friction occurs both on the threads and under the head of the bolt. If using the torque angle method with a specified torque and then turning it a specified angle, holding the degree wheel in. What the chart shows is the temendous effect of friction on applied torque value to get the same resultant pre-load. ayau, We changed the material on the camber bolts due to increasing requirements from the auto manufacturers that we supply to. Connecting Rods Installation Instructions 1. " Bolts do stretch, in fact they stretch to their yield and then shortly after they fail (break) yield is the point where the bolt can not only handle its maximum tinsel but also stretch with the head as the head heats and cools. Due to the wide variety of vehicles in which a 350HO Deluxe Engine can be installed, some procedures and recommendations may not apply to specific applications. The stretch of a bolt or metal rod loaded in tension is calculated by use of the following equation. Bolts are elastic by nature, meaning that within their elastic range, they'll stretch as the load on the bolt increases. The bolt shanks stretch when you torque them. • Torque to 33 ft-lbs • Sold individually, eight per vehicle • OEM Volkswagen. The greatest contributors to flange leakage are insufficient torque, un-even torque, and flange misalignment. Bolt tension, which causes the bolt to stretch, is what actually keeps a joint together. Once a stretch bolt is used the mechanical characteristics of the bolt are changed, the bolt is no longer within the manufacturers specified tolerance’s Recommendations Air tools should never be used to loosen or tighten the retaining bolts Always adhere to the manufacturers torque settings. On a stretch bolt permenant elongation of the bolt occurs as the material yields. Stretched bolts can damage threads in the engine, especially on aluminum blocks, and since the bolts are weakened, they may break if retorqued. Torque, as it relates to fasteners, is the twisting force required to spin a nut along the thread of a bolt. "Bolt stretch will occur when a bolt is. Billet Aluminum Rod Bolt stretch Gauge by ARP. With no lube and an old rusted lug nut, the torque gets wasted on fighting the friction. The torquing is supposed to stretch the bolts so that they are preloaded to exceed the load that occurs during engine operation. Watch carefully not to let the coils fall out and that the brake lines, ABS wires and axle vent hose do not stretch and damage to these vital parts. Sign in with Twitter. +1 When the bolts are installed they are tightened to a specific torque, and then using a torque angle meter (some torque wrenches have this built in, like the snap-on electric ones) to turn the bolt a preset number of degrees to literally stretch the bolt a certain amount for maximum clamping pressure, and no danger of snapping the bolts. The torque angle method can be accurate – but only if each individual application has been previously calibrated by direct measurement of bolt stretch. The stretch of a bolt or metal rod loaded in tension is calculated by use of the following equation. The knowledge of what makes an engine truly move a rider runs deep at The Motor Company, and it’s been put to particular good use to power the Softail family. The Bolt efficiency will be low due to wide tolerance of the tension. The bolts in a tension joint must act like clamps. When a bolt is tightened the shank sustains a direct stress, due to the elongation strain, together with a torsional stress, due to the torque acting on the threads. Typical strength calculations are. I'd like to eliminate the torque to stretch bolts. 8L turbo Has anyone had any problems with stretch bolts that mount to the engine bracket on the front motor mount (the one the power steering reservoir sits on)? I replaced my bolts but one of them wouldnt torque down. Torque is one of the most common methods of installing bolts, where the objective is to stretch the bolt to a predetermined load. Tighten the bolt firmly in that pattern for all bolts, then repeat with the proper torque (using a torque wrench). To measure the. Typically, 10% to 15% of the torque is used to stretch the bolt. We will work together with you to develop a faster, easier or safer solution for any bolting issues you may have. On this point, Sparks can get downright militant. higher the preload) the higher the resulting clamp load. I used to catch mechanics doing a retorque on a bolt that was safety wired to prevent loosening. The stretch of a bolt or metal rod loaded in tension is calculated by use of the following equation. To visualize the rotational force causing stretch in the bolt, consider that the bolt’s threads act as a wedge or an inclined plane wrapped around the bolt’s body. PRELOAD (TORQUE) RECOMMENDATIONS 8. As a nut and bolt are tightened the components to be fastened are clamped together. Bolt Torque. This process creates both twisting force and a vertical clamping force, which means that when the cylinders within the engine’s combustion chamber begin accumulating load, the bolt will both stretch and twist. The outer sleeve thrusts down against the washer to stretch the bolt and compress the gasket. Remove the stock head bolt. gaskets and stretch design of the. This clamping force, also known as pre-load, helps prevent the bolt in the bolted assembly from loosening over time due to vibration. Few realize a threaded fastener is like a spring that stretches to achieve optimum clamping tension. Before removing the whole head, try removing the bolt in question. Stretch & Stress the stud / bolt by tightening multy clamping screws. Tightening torque to preload a bolt Metric thread : M1 M1. The stretch of a bolt or metal rod loaded in tension is calculated by use of the following equation. If we tighten a bolt to a simple 'torque' we know that it will generally hold load and that we have not exceeded the material's UTS even if it is has. After the bolt is tightened to the initial torque value, it’s tightened an additional number of degrees to reach the final value. A torque wrench uses torque as a proxy for bolt tension. When you bang on a split bolt, you rearrange the conductor strands, so they fill any voids, and that loosens the tension, which is why you have to tighten it some more, and you should tighten last, not hammer last. The torque method is widely used due to its simplicity and convenience. Kia: With 201hp and 291 pound-feet of torque, the Niro EV’s electric motor packs an extra pony and an additional 25 pound-feet of torque relative to the Bolt’s. As long as the bolt is not stressed beyond its proof load (the maximum load a bolt can withstand and still behave in an elastic manner), it will return to its original length once the torque is relieved. lbs Bolt Stretch Bolt 7/16" ARP 8740. HOW DO YOU CALCULATE TORQUE? Torque is the result of multiplying the value of Force applied by the Distance from the point of application. So if a typical 3/8-inch ARP rod-bolt stretch figure is 0. stretching the bolts is a huge pain in the ass, but if you want to know its 'right' the only way to know is stretching. TORQUE SPECS: Torque 63 ft. Most of us are aware that amount of resulted bolt stretch (preload) for a particular applied torque varies greatly due to the following: Dirty/Rusty Threads – The Torque Wrench clicks (Beeps, or similar) at the preset torque setting, but the bolt is not stretched to the desired preload and the parts are not clamped sufficiently and the bolt. * Steel made bolt to solve the problem of chip, insufficient torque,. Threaded Fasteners: Torque-to-Yield and Torque-to-Angle By Bill McKnight All the original equipment manufacturers (OEMs) have fastener labs with lots of sophisticated equipment and well-educated people working on fastening issues. That has been our rule for the past 50 or so years and it has never. “Carrillo and every other quality rod. If they provide any information online, we have linked directly to it with the Website link. the first term represents the amount of torque to stretch the bolt and compress the joint the second term represents the amount of torque required to overcome the friction between the nut and bolt threads the third term represents the amount of torque required to overcome the friction on the face of nut when multiplied by the preload F. Recommeded Stretch. The additional force applied to the joint members by tightening a bolt can affect the amount of tension on the other previously tightened bolts. This is illustrated in the piechart shown above. If the turn-to-tension procedure is used to establish clamping load, it is necessary to know both the spring rate of the bolt and the spring rate of the clamped components, since turning the bolt stretches the. An article on Torque / Tension relationship from their web site is reproduced below. The torque required to tighten a rod bolt to a certain stretch is a designed-in factor reflecting the diameter and alloy of the bolt, but you cannot take away the fact that it’s indirect. All tensile forces try to stretch and/or separate the joint. I contacted Carillo for clarification and the tech stated "you may have to exceed the torque spec to acheive propper stretch". Torque Axial Force Calculator | Strength of Materials Bolt Preload Tension Force Equation & Calculator Bolt Preload Tension Force: In the tension joint, the bolt and clamped components of the joint are pre-load designed to transfer the external tension load through the joint by way of the clamped components through the design of a proper. With a special high-tension spring, this gauge remains conveniently positioned on the bolt during tightening, with adjustability for bolts up to 2. Mount the 130mm bevel bolt in the top hole of bracket. Used as is, the bolt will fail more easily than if it sat in a new bushing. This accuracy depends of course on the factors mentioned above. When a bolt is tightened the shank sustains a direct stress, due to the elongation strain, together with a torsional stress, due to the torque acting on the threads. Due to the weak dial gauge spring, getting accurate measurements pretty much requires both hands. You can see the additional torque stretching the bolt beyond its elastic limit and as such it gets thinner around the middle, or “necks”. If the engine has an aluminum cylinder head or block, however, do not re torque the head bolts until the engine has cooled back down to room temperature. Torque results from the static friction presented by the area of all mating surfaces, plus the work required to further stretch the bolt. It's very important to allow 24 hours for curing. The applied torque causes the bolt to "climb" the thread causing a tensioning of the bolt and an equivalent compression in the components being fastened by the bolt. Yet, most installations are done with a torque wrench, not a tension wrench. If the tension is too high (overstretched), the bolt could break. to gas tank and premium gas due to rough. Measuring bolt tension (indirectly via bolt stretch) is actually what is desired, but often torque is the only practical measurement which can be made. Most of the torque is Most of the torque is expended overcoming friction, 50% under head and 40% threads according to reference [36 pg. First, the bolt load-24 2 inch bolts-must be enough to seat the gasket. Bolt Basics A fastener works like a coil spring. due to restricted room in the engine compartment, your headers may come close to certain body and chassis components. Others say that it is a stretch bolt and must be replaced. I called Brian at GRP and his instructions were the stretch was the most important thing. Bolt tension, which causes the bolt to stretch, is what actually keeps a joint together. The torquing process used with the clamp nut is the same process to torque a standard nut. GRP rods have had great success in drag racing. If you were to torque the bolts in my Callies rods to 75 lbs, they would probably fail pretty quick due to being under stretched which is usually worse than or stretched. 0064" NOTES: OF ALL ROD FAILURES ARE DUE TO ONE OR MORE OF THE FOLLOWING: 1. As in angle tensioning. The point when a bolt begins to stretch without increasing the clamping load on the assembly is defined as the yield point or yield strength. This is especially useful on smaller bolts that require a relatively low torque such as rotor bolts, but can be put to use anywhere that a bolt can repeatedly loosen even though it has been. Experience has shown that various types of head bolts, i. Note: If the pointer does not remain centered over the index line during final tightening, loosen the bolt and repeat the procedure beginning with step 4. Some sources say that it is fine to re-use this bolt after removal. It is necessary to understand the difference between clamping force and the amount of torque applied to the screw or bolt. THought that I might bump this post, since it highlights the general lack of published data for keel bolt torque values. As a past GM service rep we initiated torque sticks back in the eighties to reduce the number of warped rotors warranty claims due to improper torque procedure. I know it will not be the correct sequence for tightening head bolts, but it may be OK for only one. Preload Variation: Torque Method vs. This is the most widely used method. We could lose that stretch due to relaxation because we're compressing wood. When used in a NON-gasketed installation, stretch bolts seem to meet basic clamping requirements, as long as they are not subjected to loads that exceed the humble tensile strengths of their design. I can use a stretch gauge for the rods and was told the head go to 220 lbs. Like I do with every engine, I torqued the bolts to the specified amount (50lbs) using my Snap-On torque wrench and ARP assembly lube on the threads*. Fasteners 101 - Torque Setting. On some, you start in the center and tighten down opposite bolts, one front, one rear, crisscrossing across the head. Snyder Enterprises. When loosening bolts a torque value higher than the tightening torque is normally required. Learn vocabulary, terms, and more with flashcards, games, and other study tools. On the go? Download our Bolt Load Calculator app instead. Before removing the whole head, try removing the bolt in question. 11ft lbs is for a 6mm bolt, but WAY over a 5mm bolt torque of 8 to 8. To use with the 4-Leaf Double-Eye Spring for 3,500 Pound Trailer Axles # SP-210275 I recommend the U-Bolt Kit # APUBR-1. Due to the extreme power levels of impact wrenches, most fasteners would stretch/deform/break under this extreme test, but we have specialized equipment which can handle those forces & give us. 2L 4 Cylinder. Many companies continue to preach "bigger the better" due to the fact their fasteners can achieve higher torque than others which will allow you to have a safer. Hydraulic torque wrench A hydraulic torque wrench is a power tool designed to exert torque on a fastener to achieve proper tightening or loosening of a connection through the use of hydraulics. This is the most widely used method. When loosening bolts a torque value higher than the tightening torque is normally required. In industrial situations where you are talking BIG torques, so interface friction is a big issue, you wouldn’t even torque the bolts at all, but use a hydraulic puller to stretch the bolt to the. I just did all the brakes on my son's 2007 Camry and it was pretty easy due to the info being so readily available as well as plenty of YouTube videos. Running torque should be included in the values listed in the tables because any torque puts shear load on the bolt. In addition to the approximately 12,500 rivets in the airplane, there are many hundreds of MS, NAS and AN fasteners, all of which are supposed to be torqued to spec using a torque wrench. Overtightening can also stretch the threads and prevent it being removed. The big end con rod bolts in my old K100 are spec'd like this. The fact-checkers, whose work is more and more important for those who prefer facts over lies, police the line between fact and falsehood on a day-to-day basis, and do a great job. Today, my small contribution is to pass along a very good overview that reflects on one of Trump’s favorite overarching falsehoods. Namely: Trump describes an America in which everything was going down the tubes under  Obama, which is why we needed Trump to make America great again. And he claims that this project has come to fruition, with America setting records for prosperity under his leadership and guidance. “Obama bad; Trump good” is pretty much his analysis in all areas and measurement of U.S. activity, especially economically. Even if this were true, it would reflect poorly on Trump’s character, but it has the added problem of being false, a big lie made up of many small ones. Personally, I don’t assume that all economic measurements directly reflect the leadership of whoever occupies the Oval Office, nor am I smart enough to figure out what causes what in the economy. But the idea that presidents get the credit or the blame for the economy during their tenure is a political fact of life. Trump, in his adorable, immodest mendacity, not only claims credit for everything good that happens in the economy, but tells people, literally and specifically, that they have to vote for him even if they hate him, because without his guidance, their 401(k) accounts “will go down the tubes.” That would be offensive even if it were true, but it is utterly false. The stock market has been on a 10-year run of steady gains that began in 2009, the year Barack Obama was inaugurated. But why would anyone care about that? It’s only an unarguable, stubborn fact. Still, speaking of facts, there are so many measurements and indicators of how the economy is doing, that those not committed to an honest investigation can find evidence for whatever they want to believe. Trump and his most committed followers want to believe that everything was terrible under Barack Obama and great under Trump. That’s baloney. Anyone who believes that believes something false. And a series of charts and graphs published Monday in the Washington Post and explained by Economics Correspondent Heather Long provides the data that tells the tale. The details are complicated. Click through to the link above and you’ll learn much. But the overview is pretty simply this: The U.S. economy had a major meltdown in the last year of the George W. Bush presidency. Again, I’m not smart enough to know how much of this was Bush’s “fault.” But he had been in office for six years when the trouble started. So, if it’s ever reasonable to hold a president accountable for the performance of the economy, the timeline is bad for Bush. GDP growth went negative. Job growth fell sharply and then went negative. Median household income shrank. The Dow Jones Industrial Average dropped by more than 5,000 points! U.S. manufacturing output plunged, as did average home values, as did average hourly wages, as did measures of consumer confidence and most other indicators of economic health. (Backup for that is contained in the Post piece I linked to above.) Barack Obama inherited that mess of falling numbers, which continued during his first year in office, 2009, as he put in place policies designed to turn it around. By 2010, Obama’s second year, pretty much all of the negative numbers had turned positive. By the time Obama was up for reelection in 2012, all of them were headed in the right direction, which is certainly among the reasons voters gave him a second term by a solid (not landslide) margin. Basically, all of those good numbers continued throughout the second Obama term. The U.S. GDP, probably the single best measure of how the economy is doing, grew by 2.9 percent in 2015, which was Obama’s seventh year in office and was the best GDP growth number since before the crash of the late Bush years. GDP growth slowed to 1.6 percent in 2016, which may have been among the indicators that supported Trump’s campaign-year argument that everything was going to hell and only he could fix it. During the first year of Trump, GDP growth grew to 2.4 percent, which is decent but not great and anyway, a reasonable person would acknowledge that — to the degree that economic performance is to the credit or blame of the president — the performance in the first year of a new president is a mixture of the old and new policies. In Trump’s second year, 2018, the GDP grew 2.9 percent, equaling Obama’s best year, and so far in 2019, the growth rate has fallen to 2.1 percent, a mediocre number and a decline for which Trump presumably accepts no responsibility and blames either Nancy Pelosi, Ilhan Omar or, if he can swing it, Barack Obama. I suppose it’s natural for a president to want to take credit for everything good that happens on his (or someday her) watch, but not the blame for anything bad. Trump is more blatant about this than most. If we judge by his bad but remarkably steady approval ratings (today, according to the average maintained by 538.com, it’s 41.9 approval/ 53.7 disapproval) the pretty-good economy is not winning him new supporters, nor is his constant exaggeration of his accomplishments costing him many old ones). I already offered it above, but the full Washington Post workup of these numbers, and commentary/explanation by economics correspondent Heather Long, are here. On a related matter, if you care about what used to be called fiscal conservatism, which is the belief that federal debt and deficit matter, here’s a New York Times analysis, based on Congressional Budget Office data, suggesting that the annual budget deficit (that’s the amount the government borrows every year reflecting that amount by which federal spending exceeds revenues) which fell steadily during the Obama years, from a peak of $1.4 trillion at the beginning of the Obama administration, to $585 billion in 2016 (Obama’s last year in office), will be back up to $960 billion this fiscal year, and back over $1 trillion in 2020. (Here’s the New York Times piece detailing those numbers.) Trump is currently floating various tax cuts for the rich and the poor that will presumably worsen those projections, if passed. As the Times piece reported: