JM Hardware® A325 • A490 • Heavy Hex Structural Bolt/ Industrial Bolt(Hex Head/ Tension Control Head)/Thread Rod/Anchor Bolt(Xylan & Zinc/ Aluminum Coating available)
JM Hardware® A325 • A490 • Heavy Hex Structural Bolt/ Industrial Bolt(Hex Head/ Tension Control Head)/Thread Rod/Anchor Bolt(Xylan & Zinc/ Aluminum Coating available)
JM Hardware® A325 • A490 • Heavy Hex Structural Bolt/ Industrial Bolt(Hex Head/ Tension Control Head)/Thread Rod/Anchor Bolt(Xylan & Zinc/ Aluminum Coating available)
JM Hardware® A325 • A490 • Heavy Hex Structural Bolt/ Industrial Bolt(Hex Head/ Tension Control Head)/Thread Rod/Anchor Bolt(Xylan & Zinc/ Aluminum Coating available)
JM Hardware® A325 • A490 • Heavy Hex Structural Bolt/ Industrial Bolt(Hex Head/ Tension Control Head)/Thread Rod/Anchor Bolt(Xylan & Zinc/ Aluminum Coating available)
JM Hardware® A325 • A490 • Heavy Hex Structural Bolt/ Industrial Bolt(Hex Head/ Tension Control Head)/Thread Rod/Anchor Bolt(Xylan & Zinc/ Aluminum Coating available)
JM Hardware® A325 • A490 • Heavy Hex Structural Bolt/ Industrial Bolt(Hex Head/ Tension Control Head)/Thread Rod/Anchor Bolt(Xylan & Zinc/ Aluminum Coating available)
JM Hardware® A325 • A490 • Heavy Hex Structural Bolt/ Industrial Bolt(Hex Head/ Tension Control Head)/Thread Rod/Anchor Bolt(Xylan & Zinc/ Aluminum Coating available)
JM Hardware® A325 • A490 • Heavy Hex Structural Bolt/ Industrial Bolt(Hex Head/ Tension Control Head)/Thread Rod/Anchor Bolt(Xylan & Zinc/ Aluminum Coating available)
JM Hardware® A325 • A490 • Heavy Hex Structural Bolt/ Industrial Bolt(Hex Head/ Tension Control Head)/Thread Rod/Anchor Bolt(Xylan & Zinc/ Aluminum Coating available)
JM Hardware® A325 • A490 • Heavy Hex Structural Bolt/ Industrial Bolt(Hex Head/ Tension Control Head)/Thread Rod/Anchor Bolt(Xylan & Zinc/ Aluminum Coating available)
JM Hardware® A325 • A490 • Heavy Hex Structural Bolt/ Industrial Bolt(Hex Head/ Tension Control Head)/Thread Rod/Anchor Bolt(Xylan & Zinc/ Aluminum Coating available)
JM Hardware® A325 • A490 • Heavy Hex Structural Bolt/ Industrial Bolt(Hex Head/ Tension Control Head)/Thread Rod/Anchor Bolt(Xylan & Zinc/ Aluminum Coating available)
JM Hardware® A325 • A490 • Heavy Hex Structural Bolt/ Industrial Bolt(Hex Head/ Tension Control Head)/Thread Rod/Anchor Bolt(Xylan & Zinc/ Aluminum Coating available)
JM Hardware® A325 • A490 • Heavy Hex Structural Bolt/ Industrial Bolt(Hex Head/ Tension Control Head)/Thread Rod/Anchor Bolt(Xylan & Zinc/ Aluminum Coating available)
JM Hardware® A325 • A490 • Heavy Hex Structural Bolt/ Industrial Bolt(Hex Head/ Tension Control Head)/Thread Rod/Anchor Bolt(Xylan & Zinc/ Aluminum Coating available)
JM Hardware® A325 • A490 • Heavy Hex Structural Bolt/ Industrial Bolt(Hex Head/ Tension Control Head)/Thread Rod/Anchor Bolt(Xylan & Zinc/ Aluminum Coating available)
JM Hardware® A325 • A490 • Heavy Hex Structural Bolt/ Industrial Bolt(Hex Head/ Tension Control Head)/Thread Rod/Anchor Bolt(Xylan & Zinc/ Aluminum Coating available)
JM Hardware® A325 • A490 • Heavy Hex Structural Bolt/ Industrial Bolt(Hex Head/ Tension Control Head)/Thread Rod/Anchor Bolt(Xylan & Zinc/ Aluminum Coating available)
JM Hardware® A325 • A490 • Heavy Hex Structural Bolt/ Industrial Bolt(Hex Head/ Tension Control Head)/Thread Rod/Anchor Bolt(Xylan & Zinc/ Aluminum Coating available)
JM Hardware® A325 • A490 • Heavy Hex Structural Bolt/ Industrial Bolt(Hex Head/ Tension Control Head)/Thread Rod/Anchor Bolt(Xylan & Zinc/ Aluminum Coating available)
Contact Us
  • Description
  • Parameters
Heavy Hex Bolts are designed for use in a variety of high temperature, high strength industrial applications, such as with steel fabrication and general construction. They feature a thicker head than standard or regular hex bolts, and offer a greater bearing surface that distributes the clamping load over a wider area.

Heavy hex bolts can be made with a few different materials including low and medium carbon steel, alloy, and stainless steel. They are available plain, hot dipped galvanized, phosphate, zinc or cadmium plated for additional corrosion-resistance. Additional finishes are available - please contact us for a quote.

Heavy Hex Bolt Specifications
General heavy hex bolts include ASTM A307 specifications, which covers carbon steel bolts and studs ranging from 1/4” through 4” in diameter. This is the most common heavy hex bolt and includes Grades A, B, and C which denote tensile strength, configuration, and its intended use.

The ASTM A193 specification covers alloy steel and stainless steel bolt materials for high temperature and high pressure applications.

Heavy hex structural bolts are designed for steel-to-steel connections and include ASTM A325 and A490 specifications, which covers bolts from 1/2” up to 1-1/2” in diameter. Since these heavy hex bolts are intended for structural connections, they have shorter thread lengths than standard hex bolts.
Commonly used heavy-duty bolts, nuts and washers
Heavy Structural Bolt A325 plain A325 (not plain) A490 (All surface)
Heavy Hex Nut A563 Gr.C,DH or A194 Gr.2H A563 Gr.DH or A194 Gr.2H A563 Gr.DH or A194 Gr.2H
Flat Washer F436

Production Display
Tension control structural bolts are high-strength bolts that are specifically designed for use in steel structures. They are often used in construction projects where large, heavy loads must be supported. Here are some common specifications for tension control structural bolts:

Size: Tension control structural bolts typically range in diameter from 1/2 inch to 1 1/4 inch. The most common diameter is 3/4 inch.
Length: The length of tension control structural bolts varies depending on the application. They can range from a few inches to several feet.
Strength grade: Tension control structural bolts are typically made from high-strength steel with a strength grade of either A325 or A490. A325 bolts have a minimum tensile strength of 120 ksi, while A490 bolts have a minimum tensile strength of 150 ksi.
Coating: Tension control structural bolts are often coated with a protective coating to prevent corrosion. Common coatings include hot-dip galvanizing, mechanical galvanizing, and black oxide coating.
Tension control system: Tension control structural bolts use a unique tension control system that ensures that the correct tension is applied to the bolt during installation. The tension control system consists of a special washer and a hexagonal head that is designed to shear off when the correct tension is reached.

Standards: Tension control structural bolts are manufactured in accordance with standards established by organizations such as ASTM International, the American Institute of Steel Construction, and the Research Council on Structural Connections. These standards ensure that the bolts meet certain specifications for strength, durability, and safety.



JM Hardware® provides free samples of the above products during the Black Friday event. If you have any demand for these products, please contact our email: xarella.huang@jm-industry.com


Brand Story


The inception of the JM Hardware® brand was a profound moment born out of a fateful business trip. During a trip abroad, I was flipping through a newspaper when I came across a heartbreaking story about a steel building that had collapsed due to a batch of substandard fasteners. The tragic images and casualties left an indelible mark on me.

From that moment on, our commitment to putting product quality first became a cornerstone of JM Hardware®, engraved in the DNA of our brand. With this unwavering commitment, JM Hardware® set out to set a new standard for quality. We spend countless hours researching, developing, and testing each product to ensure that they not only meet industry standards, but that they also meet the company's own higher standards. This journey is driven not by profit, but by a deep sense of responsibility - the responsibility to protect a person, a family, a community.

JM Hardware® stands as a testament to that enduring commitment. Every product that bears the JM Hardware® name will be synonymous with excellence, durability and safety.

JM Hardware®: the combination of quality and integrity.

-------- Mrs. Xarella Huang

General President

  • 2006
    Established
  • 34000T
    Production Quantity Each Year
  • 85+
    Export Country
  • 850 +
    R&D New Products
Why Choose Us
  • Supply one-stop service & DDP term
    Help clients purchase other products,realize door-to-door service to make international procurement more convenient
  • Strong R&D Capability
    Successfully developed 850+ new products in past 18 years
  • Mature & professional service teams
    Provides 24/7 online and offline services for you,70%stuff have 5+ working experience in JM
  • Rich Industry Experience
    JM has the rich experience to supply the high quality fasteners to Project contractor
  • Registered trademarks
    Register JM Hardware ® in USA,EU ,UK,Quality Assurance
  • Rich export experience
    18 years exported to 85+ countries
Quality Control

JM Hardware conducts product quality control in strict accordance with ISO 9001 standards to ensure that our products meet high quality standards. Below are our five quality control steps:

Step 1: Incoming material control

We carry out strict incoming material control by conducting dimensional tests on each batch of raw materials and checking the raw material reports from the steel mills. This ensures that the raw materials we use are within specification and provide a reliable basis for production.

Step 2: First part control
After the mold assembly is completed, we conduct a thorough inspection of the first production part and make detailed records. Only qualified first parts can be released to start mass production. This step ensures that the quality of the product meets the standard at the beginning.

Step 3: Self-inspection by workers during mass production
In the mass production process, we require the workers of each machine to carry out self-inspection every hour. If any substandard product is found, we will immediately pick or scrap the production within this hour until the problem is solved and meets the standard of conformity, and then we can continue the production. This self-inspection mechanism helps to find and solve problems in time during the production process.



Step 4: QC inspection during mass production
In addition, every two hours, the quality inspection personnel will carry out random inspection on the products of each machine. Only qualified products can continue to flow into the next production stage. If non-conforming products are found, we will take the same selection or scrapping measures and ensure that the problem is properly handled. This helps provide additional quality assurance.

Step 5: Finished product control
Finally, after each batch of finished product is made, we conduct random inspections in proportion to the order. Qualified products will be packaged and put into storage, while unqualified products will be returned for further analysis and rectification. We insist on ensuring that the quality of our products meets high standards so that we can provide reliable products to our customers.

Step 6: Non-conforming goods management
According to the process of JMhardware's non-conforming products handling, pick or scrap. And the problem of rectification and tracking reasons to ensure that non-conforming products will not flow into the market.

These quality control measures constitute JM Hardware's quality management system, and we are constantly striving to improve the quality of our products and are committed to meeting the needs of our customers. We believe that quality control is the key to our success.


Production Equipment
Testing Equipment
Test report
Packing
  • JM Small Box & JM Carton
  • Small bag with lable & Nature carton
  • Small box & Nature carton
  • 90kgs Metal keg & Wood solid pallet
  • Wood case & Plastic keg with wood solid pallet
  • Fumigation wood pallets & Non fumigation pallets
  • Paper sleeve & Plastic bag + Non fumigation pallets
  • Wooden case& Woven bag + Non fumigation pallets
  • Container Packing



Our vision is to make JM Hardware® a well-known Chinese brand of high-end hardware parts in the world,and your cooperation will be an important part of it

If you do not see the product you need, or you have special customization requirements, you can send an email to xarella.huang@jm-industry.com. JM Hardware® will do our best to help you solve the problem

Heavy Hex Structural Bolt ANSI/ASME standard DIN standard
Diameters of Heavy hex structural bolts
Nominal Size
or Basic
Major Dia of
Thread

E F G H R LT Y Total Runout of Bearing Surface FIM
Body Diameter Width Across Flats Width Across Corners Head Height Radius of Fillet Thread Length Transition Thread Length
Max Min Nominal Max Min Max Min Nominal Max Min Max Min
1/2  0.5000 0.515 0.482 7/8 0.875 0.850 1.010 0.969 5/16 0.323 0.302 0.031 0.009 1.000 0.190 0.016
5/8  0.6250 0.642 0.605 1-1/16 1.062 1.031 1.227 1.175 25/64 0.403 0.378 0.062 0.021 1.250 0.220 0.019
3/4  0.7500 0.768 0.729 1-1/4 1.250 1.212 1.443 1.383 15/32 0.483 0.455 0.062 0.021 1.380 0.250 0.022
7/8  0.8750 0.895 0.852 1-7/16 1.438 1.394 1.660 1.589 35/64 0.563 0.531 0.062 0.031 1.500 0.280 0.025
1   1.0000 1.022 0.976 1-5/8 1.625 1.575 1.876 1.796 39/64 0.627 0.591 0.930 0.062 1.750 0.310 0.028
1-1/8  1.1250 1.149 1.098 1-13/16 1.812 1.756 2.093 2.002 11/16 0.718 0.658 0.930 0.062 2.000 0.340 0.032
1-1/4  1.2500 1.277 1.223 2 2.000 1.938 2.309 2.209 25/32 0.813 0.749 0.930 0.062 2.000 0.380 0.035
1-3/8  1.3750 1.404 1.345 2-3/16 2.188 2.119 2.526 2.416 27/32 0.878 0.810 0.930 0.062 2.250 0.440 0.038
1-1/2  1.5000 1.531 1.407 2-3/8 2.375 2.300 2.742 2.622 15/16 0.974 0.902 0.930 0.062 2.250 0.440 0.041
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