F959M Tension Indicating Washer

Specification

HIGH-STRENGTH STRUCTURAL BOLTING ASSEMBLIES FOR PRELOADING - PART 9: SYSTEM HR OR HV - DIRECT TENSION INDICATORS FOR BOLT AND NUT ASSEMBLIES

High strength structural bolting for preloading

Part 9: System HR or HV - Direct tension indicators for bolt and nut assemblies

INSTALL AND USE

THEORY OF PRELOADED BOLTING ASSEMBLIES The principle of Preloaded bolted connections relies upon tensioning each bolt in the connection to a specified minimum preload so that the required clamping force will be induced at the connection interface. Shear loads are then transferred by frictional resistance at the joint interface rather than by bearing on the bolt shanks and hole faces. In this type of connection there will be no movement of the connected materials when the connection is subjected to these loads.

When axial tensile loads are applied to the bolt through the bolted connection, preloading of the connection to a specified minimum is also important, particularly if the loads are cyclical and could induce loosening or fatigue failure of the bolts. The clamping force developed at the specified minimum bolt preload should be greater than the applied loads. This will prevent the plies from separating or the bolts from developing any significant increase in axial tensile stress over the installed preload stress.

TIGHTENING OF PRELOADED ASSEMBLIES The essential requirement for preloaded connections is that the individual bolts are correctly tightened to the specified minimum preload; EN 1993.1.8 (Eurocode 3) specifies that to develop the necessary clamp force in the connection each bolt must be preloaded to 70% of the nominal bolt tensile strength. The permitted methods of preloading in EN 1090-2 are dependent on either movement of the nut along the bolt thread by a specified amount or the application of a calculated value of torque (turning moment) to the nut. Methods that depend on displacement of the nut: 1. The DTI method depends on the deformation of protrusions that have been extruded from the face of a washer. The DTI is calibrated so that when a specified average gap is reached the required preload is achieved. 2. The Highways Agency part-turn method requires each bolt to be tightened by torque to bring the steelwork into contact (each bolt diameter uses a different torque value). A part-turn, a minimum of a half turn, is then applied to develop the required preload. Methods that depend on the application of torque: 1. The Combined method requires the bolt to be torqued to 75% of the required preload; the required torque is calculated from data obtained from the EN 14399-2 – Fitness for Purpose test. A small part-turn, less than one third turn, is then applied to develop the required preload. 2. The Torque Control method again uses a value of torque calculated from data obtained from the EN 14399-2 – Fitness for Purpose test. 3. The bolts with the HRC method (TC bolts) are tightened using a special wrench where the nut is rotated while reacting against the splined bolt end. The HRC bolts are calibrated so that when the nut stops rotating the spline shears at a breakneck and the required preload is achieved.

PACKING

QBH BULK

20-25KG/CTN,36CTNS/PALLET

20-30KG/BAGS,36BAGS/PALLET

ONE TON/BOXES

50KG/ IRON DRUM,12 IRON DRUMS/PALLET

QBH SMALL PACKING

Packing in small boxes according to customer’s requirements

Packing in plastic bag according to customer’s requirements

QBH PALLET TYPE

SOLID WOOD FUMIGATION PALLET

EURO Pallet

THREE SPLINT PALLET

WOODEN BOX

The advantages of QBH

• QBH brand sales to the main quality assurance.
• Years of export trade management, excellent service, word-of-mouth guarantee.
• By working with TUV,escort for quality.
• Customization of non-standard parts can be made according to customer's requirements and drawings.
• For quality customers,we can provide a certain credit period.

     Jiaxing City Qunbang Hardware Co,ltd is a productiondesignsales and after-sales as one of the fasteners business,The company is located in HangjiaHu Plain,close to ShanghaiNingboZhapu ports.The geographical position is superior,the transportation is convenient,has created the natural superiority for the export.

     The company mainly produces high-strength fasteners business, bolts and nuts are the main,the main standard are DIN/ANSIASME/JIS/UNI/ISO/AS/BS/GB and so on.The product massively applies in the bridgeroadthe petroleum pipeline facilitythe wind power generation and steel structure project. Carbon steel bolts mainly have 4.8、5.8、6.8、8.8、10.9、12.9,nuts mainly have 4、6、8、10,the main material of stainless steel fastener is 201304316.QBH from its establishment to he present,after ten years of development,it is equipped with perfect testing equipment,and SGS and TUV have a good cooperation,each batch of products is accompanied by a 3.1 or 3.2 certificate,further escort the quality of the company.

        In 2017,we registered the trademark “QBH” in the CHINA、EU、United States,and has six fastener product patents,has obtained the Zhejiang Province science and technology small and medium-sized enterprise certificate as well as the ISO9001:2000 cerfiticate.With the continuous development and expansion of the company,as well as customer demand for product diversification,on the basis of its original production,in order to further enhance the potential for cooperation with customers,as well as to provide competitive prices.Starting in 2015,QBH has taken part in several fastener enterprises one after another,the product variety is more abundant and the price is more advantageous,and the quality can also be well controlled. QBH has always been to provide customers with efficient and convenient service and quality products,and create a pleasant trading process for customers for the mission,deeply participate in customer construction projects and make progress together with customers,this means that we need to provide better and more cost-effictive solutions,so as to help customers stand out from the competition.

         QBH promises to always provide you with excellent quality,efficient service and very competitive prices.We believe that the cooperation between us is not only based on business,but also hope that we can open new markets on the basis of win-win situation.And thank all the customers in the past to give us great support and help,make us grow up gradually,at the same time also hope that in the nere future,and you can establish new business relations.