Pdf carbon steel bolts have been broadly utilized in modern building construction. This specification covers two types of bolting grades quenched and tempered, manufactured from high strength alloy steel. Bolt stud grade markings and strength chart aall american. These grade numbers represent the minimum yield strength ksi requirement of the anchor bolt.
Jun 05, 2020 a grade 8 bolt is the highest grade sae bolt. Feb 21, 2017 grade a490 is the astm f16 grade 3 or astm f2833 grade 1. The purpose of this procedure is to set forth the method of identifying high strength bolts, nuts, and washers by the manufacturers markings. These fasteners are available in metric, bsw, bsf, unc and unf threads. Due to the tension in the bolt, the interface between the plies steel members in a joint cannot move. These bolts are made from mediumcarbon steel, supplied in sizes m16 to m36, inclusive. The effect of a number of variables upon the ultimate shear strength and deformation at ultimate load was studied. These coatings have undergone extensive hydrogen embrittlement research in accordance with ifi 144. It defines mechanical properties for bolts that range from 1. An astm a325 or a490 bolt, an astm f1852 or f2280 twistofftype tensioncontrol bolt or an alternativedesign fastener that meets the requirements in section 2. In our product range we offer stainless fasteners ranging from strength class 8.
Proof strength about 90% of yield, ultimate tensile strength bolt fails in stretch, yield strength bolt begins to get a permanent set and changes. Type 3 for weathering steel and type 1 for bolts of other high strength steel compositions. The chart shown in figure 3 summarises the experience of the susceptibility of common fastener strength grades to he. Guidelines for use of high strength friction grip hsfg.
Moreover, high strength bolts offered certain advantages in strength and performance as compared with rivets. While tension and high clamping force are critical for joints, applied forces often cyclic can significantly reduce preload. Only astm f3125 grade a325 designated high strength bolts are permitted to be galvanized. Highstrength structural bolting assemblies for preloading. All galvanized high strength bolts and nuts shall be shipped as an assembly together in the same container. High strength bolting canadian institute of steel construction. Specification for structural joints using highstrength bolts. The tensile strength can easily be converted between both types of thread pitch by recalling that a grade 2 bolt possesses the same tensile strength as a class 4.
As the vast majority of u bolts are subject to a tensile service load, tensile strength is the primary determining factor of grade, material and diameter selection. While tension and high clamping force are critical for joints. Pdf physical properties of highstrength bolt materials at elevated. Astm a490 bolts are intended for used in structural connections similar to astm a325a325m but being produced from alloy steel instead of medium carbon steel, possed high tensile strength. Steel, 36, 55, and 105ksi yield strength is probably a more common choice today, however. Black phosphated, zinc plated, yellow zinc plated, cadmium plated, nickel plated, chromium plated and hot dip galvanized.
Moreover, high strength bolts offered certain advantages in strength. Grade 8 bolt capability in yield stretch,000 lbs in2 x. Nut installation introduction of fasteners when high. It is made of medium carbon steel, quenched and tempered. Superhighstrength bolt, shtb nippon steel corporation. Bolt and nut assemblies conforming to this part of this european standard have been designed to allow. The remaining three bolts were marked a 490 per type 1 classification in astm specification a 490 3. These steel grades are suitable for cold forming of structural and safetyrelated automotive components. No matter the system used to grade the bolts, the higher the number means the stronger the bolt. Duplex grades can be designed to have a life span of over 100 years. Compared to a grade 5 bolt, a grade 8, socket head cap screw or grade 9 bolt would increase the bolt strength roughly 2550%. The bolt is tightened with a prescribed rotation pastthe snug.
Notice on the sae j429 grade 5, astm a325 and astm a449 specifications. However, the head does usually have nine dots or lines upon them. There are different types of strengths listed for each grade. While high strength bolts are one of the most important elements of the structural system of modern steel frame. Mechanical properties of externally threaded fasteners. Grade 8 bolts have a minimum tensile strength of 150,000 psi. Astm f3125 f3125m19e2, standard specification for high strength structural bolts and assemblies, steel and alloy steel, heat treated, inch dimensions 120 ksi and 150 ksi minimum tensile strength, and metric dimensions 830 mpa and 1040 mpa minimum tensile strength, astm international, west conshohocken, pa, 2019. Astm a325 bolts dimensions chart, strength, grade a325. A high strength structural bolt of size m24, length 140 mm, property class 88 and galvanized shall be designated as. This meant that it was more expensive to install a rivet than to install a high strength bolt. Whats the difference between high strength bolt and. When youre dealing with grade 8, these are throughandthrough heated bolts so theyre treated for strength. These specifications cover the 300 series stainless steels and high manganese and high silicon austenitic. Grade bb bolts, studs alloy steel, quenched and tempered 14 thru 212234 thru 4 80,000 75,000 83,000 78,000 105,000 100,000 astm a354 grade bc 105,000 95,000 109,000 99,000 125,000 115,000 sae j429 grade 7 bolts, screws medium carbon alloy steel, quenched and tempered4 14 thru 112 105,000 115,000 3,000 sae j429 grade 8 bolts, screws, studs medium carbon.
Once tightened, the bolts will remain tight and maintain the permanent strength of the joint. High tensile hexagonal head fasteners are available in 8. Head marking grade and material nominal size range inches mechanical properties. Astm a325 bolt strength are summarized in the table bellow inluding tensile strength, yield strength and hardness, etc. Their values are lower due to less thread engagement than that of hex and heavy hex nuts. Astm f3125 f3125m 19e2 standard specification for high. The revision to asnzs 1252 was undertaken by standards committee me029. For more information on the f16 coating, please contact the fastenal. High strength structural bolts alloy steel, quenched and tempered 12 thru 112 120,000,000 150,000 min 170,000 max no grade mark iso r898 class 4. Unlike other bolt standards, f3125 was not issued to cover a new product. Bolts in tension should exert as much force on the joint as it and the joint members will stand4. Second, the different grades have a meaning to them. Standard bolt identification markings allpro threaded.
Astm a453 660 grade a,b or d a heat treated and age hardened version of a286 is a popular high temperature precipitation hardened alloy. Astm f1554 99 standard specification for anchor bolts. The mechanical property of bolts, screws and implant bolts varies as the temperature. We have delivered fasteners with a strength exceeding class 15.
Using high strength bolts for structural bolting the. Nut tests effect of washers on torque of a325 bolts. As a comparison, the astm a325 bolt is roughly equivalent to the sae grade 5. Acronym meaning 2h nut nut strength level designation astm a194 grade 2h heavy hex nut 6g class of thread fit for metric screws 6h class of thread fit for metric nuts 8. A high strength, corrosionresistant alloy solves fastener. These steels are not considered alloy steels, even though their desired properties are achieved by the. There are three grades within this specification, 36, 55, or 105. It has both excellent corrosion resistance and high strength. Specification for stainless steel bolts, hex cap screws and studs covers the broad range of commercial ferritic, martensitic and precipitation hardened grades of stainless steel, 0. High strength bolts august 1, 2014 includes april 2015 errata supersedes the december 31, 2009 specification for structural joints using highstrength bolts. Weights of jis b1186 grade f10t high strength friction grip hex bolts, nuts and plain washers w. High strength classes and grades hexagon bolts jis bli86 combination of grade according to mechanical properties of component parts classes of sets class according to mechanical properties class 2 boit f 10t tensile strength nmm2 1200 min. Absence of heavy stress concentration due to absence of bearing between bolts and plates.
As bolts are in tension, it does not permit loosening, thus making it most ideal where vibrationsareinvolved. Grade 7 bolts, screws medium carbon alloy steel, quenched and tempered4 14 thru 112 105,000 115,000 3,000 sae j429 grade 8 bolts, screws, studs medium. These instructions are also valid when dtis are specified for use with high strength bolts in other connections as a device to ensure that all bolts. A rule of thumb is to load the bolt to 60% of the materials yield strength 5. Bolts under this specification can conform to a headed bolt, straight rod or bent anchor bolt configuration. Hardness as a method of estimating tensile strength is not as reliable as a standard tensile test. The terms used to describe the strength and load bearing properties of a metal fastener are. Bumax 88 can also be delivered ce marked according to en 15048. The high strength level gives potential for considerable weight reduction and a costeffective way to. Strength grade designations 5 2122 breaking and yield loads of ajax bolts 6 2336 ajax bsw bolts as 2451 24 ajax cup head bsw bolts asb108 25 ajax unified high tensile hexagon head 2629 bolts and set screws as 2465 ajax metric hexagon commercial 3031 bolts and set screws as1111 ajax metric hexagon precision 3234 bolts and set screws as1110. The party responsible to ensure that the contractor has satisfied the provisions. Studies of the behavior of highstrength bolts and bolted joints, core. Specification for structural joints using highstrength bolts, august 1, 2014 research council on structural connections viii vu required strength in shear factored shear load, kips db nominal diameter of bolt, in. Mechanical properties of fasteners made of carbon steel and alloy.
Pdf bolted bearing connection with high strength steel. In general, the higher the strength of the steel, the greater is the susceptibility to hydrogen embrittlement. Instruction manual for installing highstrength bolts. This is a great opportunity for those interested in corrosion resistant high strength structural bolts. High strength alloy steel 14 1 12 145000 180000 155000 c38 c42 307a astm a307 grade a bolts, screws, studs general engineering low or medium carbon steel 14 4 33000 60000 36000 b69 b100 307b astm a307 grade b bolts, screws, studs flanged joints low or medium carbon steel 14 4 33000 60000 36000 b69 b95. Type 2205the most widely used duplex ferriticaustenitic stainless steel grade. There are several grades of bolts but the three common grades for sae are 2, 5 and 8. Despite the high strength our unique materials offers a unique combination of ultra high strength and good ductility. Pdf bolted bearing connection with high strength steel and.
Specification for structural joints using high strength bolts. Basically, this is equal to like a carriage bolt strength, a grade 2 or better, a little bit better than a grade 2, but standard alloy. Additionally, the astm specification f1554 grade 55 is commonly referred to as being manufactured from a high strength, low alloy steel. Astm a325 is an astm international standard for heavy hex structural bolts, titled standard specification for structural bolts, steel, heat treated, 120105 ksi minimum tensile strength. The high strength and oxidation resistance up to 1500 degrees f. Mechanical properties of steel bolts, screws and studs. A high strength structural bolt of size m24, length 140 mm, property class 8. The bolts must average a minimum of at least 5% over the required pretension. For most standard threaded fasteners, shear strength is not a specification even. The mechanical properties are given for tests at room temperature. High strength friction grip bolts hsfg bolts are high strength structural bolts which have been tightened such as to induce tension in the bolt shank. For more information on the f16 and f2833 coatings, please contact the feds group. Bolted bearing connection with high strength steel and grade 12.
Nuts of a higher property class can generally be used in the. A total of 15 bolted connections fabricated from three grades of high strength steel with the. In a maintenance type application, and sometimes even in an oem design situation, a bolt failure often leads people to opt for a stronger bolt class or grade to prevent future failures. The anchor bolts are furnished in three strength grades, two thread classes, and in the sizes speci.
1380 85 1415 5 159 278 91 954 1455 1126 524 28 859 1250 111 1187 1412 1508 1486 937 31 897 1161 1350 587