The hsfg bolts are called as the high strength friction grip bolts. These bolts are intended for use in structural connections and therefore have shorter thread lengths than standard hex bolts. Traditionally such connections have been known in the uk as high strength friction grip hsfg connections. Approximate masses of ordinary bolts, nuts and washers. All bsi british standards available online in electronic and print formats. The sizes of specimens are based on the standard test specimen in the recommendations on design, construction, and maintenance for the friction type high strength bolted connections6.
This is a new field for indian railways and lots of issues have been raised by the users, designers and field engineers. Bs 4395 specification for high strength friction grip bolts and associated nuts and washers for structural engineering has been replaced by bs en 14399 high strength structural bolting assemblies for preloading. Ln the same period, the research council on structural connections has developed two new specifications for structural joints using astm a325 or a490 bolts, one based on allowable stress principles and the other on a load factor and resistance design philosophy. 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. Scope and field of applicetion covers the requirements for large series hexagon, high strength structural steel bolts in property classes88 and 109and in the size range m16 to m36 with short thread lengths suitable for use in both friction type and bearingtype structural steel joints. All of these bolt grades are generally used in connections subject to static forces and moments. They are widely demanded in the automobile, chemical, power plant and other related industries, and are known for their uniform thickness. Here is some useful information relating to high strength friction grip bolts. Highstrength structural bolting assemblies for licensed.
However, they may be used where oversized or slotted holes are used to increase tolerances during assembly. These bolts should be tightened to their proof loads and require hardened washers to distribute the load under the bolt heads. Full list of suppliers of high strength bolting assemblies for preloading part 4 system hv hexagon bolt and nut assemblies the european law 20096ce regulates the use of cookies. The explanation for this mechanism is the same as in friction grip. The introduction of high strength steels has increased the types and grades of bolt available to the designer. Weights of jis b1186 grade f10t high strength friction grip hex bolts, nuts and plain washers w. Advantages of high strength bolts high strength friction grip hsfg bolts have replaced the rivets because of their distinct advantages as discussed below. In this video i have explained the shear capacity of high strength friction grip hsfg bolts along with one solved example. Bs4395196916244specification for high strength friction grip bolts and associated nuts and washers for structural engineering. High strength friction grip bolts hsfg bolts latest. The range of bolts now includes ordinary strength steels bolts such as grades 4. What is the difference between normal bolts and high.
We supply a wide range of high strength friction grip bolts, circular washers and nuts. There has been need to modify certain provisions to ensure smooth. Advantages of high strength bolts high strength friction grip hsfg bolts have from ceng 3012 at indian institute of technology, kharagpur. Due to the tension in the bolt, the interface between the plies steel members in a joint cannot move relative to each other because of the friction resistance. High strength friction grip hsfg bolts design of steel. Isi handbook for structural engineers part 4 use of high strength friction grip bolts number of amendments.
Behaviour of pretensioned bolts in friction connections x load while i was writing the following chapters. High friction grip bolts are commonly used in structural steelwork. Guidelines for use of high strength friction grip hsfg. Bolt tension develops friction grip in connecting structural members, preventing slippage under service loadings be it static or dynamic. Techniques like quenching and tempering are used to achieve their high strength. Do inclined rock bolts perform better than rock bolts normal to joints. Treated with highfriction inorganic zincrich paint abstract. The astm a325 bolt specification covers high strength heavy hex structural bolts from 12. Astm f16 coating usage was added to the specification. Most manufacturers have ready tables for the bolt lengths depending upon the steel plates to be gripped. Nonpreloaded and preloaded hsfg bolts as specified in bs 439518.
En 143993 preload bolt assemblies hr high strength structural bolting assemblies for preloading previously know as high strength friction grip hsfg we are a manufacturer of ce marked preloaded fasteners to en 14399. High strength friction grip fasteners hex bolts with. The first year of a five year study of the behaviour of high strength friction grip bolted joints under the combined action of continuous loading and weathering is reported. The guidelines for use of high strength friction grip bolts hsfg on bridges on indian railways was issued in june2012. High strength friction grip bolts and nuts tubecon. Bolted connections i version ii 33 5 high strength friction grip bolts hsfg provide extremely efficient connections and perform well under fluctuatingfatigue load conditions.
What is the difference between normal bolts and high friction grip bolts. These bolts are known to have high strength and are made out of medium carbon steel. Bs 4395 has three parts and bs en 14399 has six parts with a further three parts to be released standard description. Furthermore, my other colleagues deserve thanks for support, distraction and amusement. If the link fails, the document cannot be downloaded, please click on the broken link to let us know. What are the differences between rock dowels and rock bolts. This edition of the councils specification for structural joints using highstrength bolts continues the tradition of earlier editions.
What are the advantages of using high strength friction. Pdf the high strength friction grip property class 8. Select a product to see suppliers, manufacturers, distributors, technical data for high strength friction grip fasteners, hex bolts with large width across flats for high strength strctural bolting, hex nuts for high strength structural bolting, plain washers for steel sctructures chamfered, square. In our facility in leeds, we can ce approve assembly test to en 143992 hr assemblies from m12 to m36 up to grade 10. We are the manufacturer of high tensile bolts in india. Variability of installed tension and potential resulting effects on the friction type connections behaviour conference paper pdf. High strength structural bolts high strength friction. The function of a structural bolt is therefore to provide friction grip and not itself to be subject to shear stress. For connections subject to fatigue friction grip connections with high strength bolts such as grades 8. Are washers necessary for proper operation of bolts. Is it desirable to use concrete of very high strength i.
A high strength structural bolt of size m24, length 140 mm, property class 88 and galvanized shall be designated as. Theyre also recognised for their crack proof nature. The bolts are tightened to a shank tension so that the transverse load across the joint is resisted by the friction between the plated rather than the bolt shanks shear strength. The shear capacity given in the tables must be reduced for large packings, large grip lengths. En 14399 preload bolt assemblies ce marked highstrength. Astm f2280 bolt assemblies were added to the specification. The bolts are tightened to a shank tension so that the transverse load across the joint is resisted by the friction between the plated rather than. Hsfg bolts manufacturer high strength friction grip bolts. They normally consist of high tensile strength bolts and nuts with washers. Hsfg bolts high strength friction grip bolts bolts. Using this website means you give your consent to our use of cookies. Highest grade friction grip hsfg bolt loading capacities. They were modified to make them load indicating by the method illustrated in figure 2, which was the development of the system described in reference 6. These bolts are fabricated by us using high grade materials, which are procured by us.
High strength friction grip bolts and associated nuts and washers for structural engineering. Secure pdf files include digital rights management drm software. Specification for high strength friction grip bolts and associated nuts and washers for structural engineering. Advantages of high strength bolts high strength friction. Research design and standards organization, lucknow. We can provide high strength friction grip washers which are perfect for tolerating heavy loads on thin sheet metal. Legally binding document step out from the old to the newjawaharlal nehru invent a new india using knowledge. Tensioning of high strength structural bolts high strength structural bolts are designed to permanently stretch in the grip threads, between the underside of the nut and the unthreaded portion of the shank, during tightening. The bolting type used for this type of connection is commonly called high strength friction grip hsfg bolting. Preloaded bolts are seldom used in buildings, where fatigue and slip in service are less critical.
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