This specification covers two types of quenched and tempered, steel, metric heavy hex structural bolts having a minimum tensile strength of 830 MPa (Note 1).

Formerly under the jurisdiction of Committee F16 on Fasteners, this specification was withdrawn in May 2016 and replaced by Specification F3125/F3125M for High Strength Structural Bolts, Steel and Alloy Steel, Heat Treated, 120 ksi (830 MPa) and 150 ksi (1040 MPa) Minimum Tensile Strength, Inch and Metric Dimensions. Specification F3125/F3125M supersedes and replaces specifications; A325, A325M, A490, A490M, F1852 and F2280. The unified Specification F3125/F3125M corrects known inconsistencies in the original documents and the combination will assure that requirements of the products covered under the original standards stay aligned.

ASTM Standards

A153/A153M Specification for Zinc Coating (Hot-Dip) on Iron and Steel Hardware

A563M Specification for Carbon and Alloy Steel Nuts (Metric)

A751 Test Methods, Practices, and Terminology for Chemical Analysis of Steel Products

B695 Specification for Coatings of Zinc Mechanically Deposited on Iron and Steel

D3951 Practice for Commercial Packaging

F436M Specification for Hardened Steel Washers (Metric)

F606M Test Methods for Determining the Mechanical Properties of Externally and Internally Threaded Fasteners, Washers, and Rivets (Metric)

F788/F788M Specification for Surface Discontinuities of Bolts, Screws, and Studs, Inch and Metric Series

F959M Specification for Compressible-Washer-Type Direct Tension Indicators for Use With Structural Fasteners (Metric)

F1136M Specification for Zinc/Aluminum Corrosion Protective Coatings for Fasteners (Metric)

F1470 Practice for Fastener Sampling for Specified Mechanical Properties and Performance Inspection

F1789 Terminology for F16 Mechanical Fasteners

G101 Guide for Estimating the Atmospheric Corrosion Resistance of Low-Alloy Steels

ASME Standards

B 1.13M Metric Screw Threads

B 18.18.3M Inspection and Quality Assurance for Special Purpose Fasteners

B 18.2.3.7M Metric Heavy Hex Structural Bolts

B 18.24 Part Identifying Number (PIN) Code System Standard for B18 Fastener Products

Process flow

Cold forging

Annealing treatment(if need) ➨ wiredrawing ➨ clod forging ➨ thread rolling ➨make heat treatment ➨ Finish ➨ Packing

Hot forging

Cutting material ➨ hot forging ➨ turning ➨ shrink diameter(half thread) ➨thread rolling ➨ make heat treatment ➨ Finish ➨ Packing

Product Grade

Grade 8S Grade 10s

Materials and Chemical compstition

1035

1045

40CR

Finish

PLAIN ZP YZP BLACK HDG DACROMET GEOMET CHROME NICKEL AND SO ON

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.
  

General:

In brief Type 3 grade A325 bolts shall be marked “A325” to distinguish them from standard grade A325s. Likewise Grade A490 bolts are available in diameters from 1/2 to 1-1/2 inch diameters with a minimum tensile strength of 150,000 PSI for all diameters, and are offered in two types.

In Fact ASTM A325 is an ASTM International standard for heavy hex structural bolts, titled Standard Specification for Structural Bolts, Steel, Heat Treated, 120/105 ksi Minimum Tensile Strength. It defines mechanical properties for bolts that range from ¹⁄₂ to 1 ¹⁄₂ inches (13 to 38 mm) in diameter.

In accordance with ASTM A325, all threaded components of the fastener assembly must be galvanized by the same process and the supplier’s option is limited to one process per item with no mixed processes in a lot.

This Specification deals principally with two strength grades of high-strength
bolts, ASTM A325 and A490, and with their design, installation and inspection in
structural steel joints. Equivalent fasteners, however, such as ASTM F1852
(equivalent to ASTM A325) twist-off-type tension-control bolt assemblies, are
also covered. These provisions may not be relied upon for high-strength fasteners
of other chemical composition, mechanical properties, or size. These provisions do
not apply when material other than steel is included in the grip; nor are they
applicable to anchor rods.
This Specification relates only to the performance of fasteners in structural
steel joints and those few aspects of the connected material that affect this
performance. Many other aspects of connection design and fabrication are of equal
importance and must not be overlooked. For more general information on design
and issues relating to high-strength bolting and the connected material, refer to
current steel design textbooks and the Guide to Design Criteria for Bolted and
Riveted Joints, 2 nd Edition (Kulak et al., 1987).

     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.