Hex Cap Screw Bolt
This product adopts hexagonal head design, which provides greater torque transmission ability and ensures safe and reliable fastening effect. The products are made of high-quality and high-strength nickel-based alloy materials, which provide excellent durability and tensile strength and are suitable for various high-temperature and corrosion-resistant environments.
Heavy Hex Head Bolt
Heavy hex head bolt is manufactured by the cold heading and hot forming technologies in nominal diameters ranging from 1/8"- 3" (M3 – M80). We offer fasteners in both USCS/Imperial and metric sizes. Heavy hex head bolt meets applicable ASTM, ANSI, ASME, SAE, API, NAS, AN, MS, NACE, ISO, DIN, and KS standards.
Round Bend U Bolts
Round bend u bolts are manufactured in nominal diameters ranging from 1/8"- 3" (M3 – M80). We offer fasteners in both USCS/Imperial and metric sizes. Round bend u bolts meet applicable ASTM, ANSI, ASME, SAE, API, NAS, AN, MS, NACE, ISO, DIN, and KS standards.
Plugs and Bushings
Plug and bushing are manufactured by cold heading and hot forming technology, and the nominal diameter ranges from 1/8 "to 3"(M3 to M80). We provide plugs and bushings in USCS/ English and metric sizes. Our fasteners meet the applicable ASTM, ANSI, ASME, SAE, API, NAS, AN, MS, NACE, ISO, DIN and KS standards.
Carbon Steel
Because of their low cost and general-purpose strength, carbon steel bolts are one of the most commonly utilized types of bolts.
Grades such as Grade 2, Grade 5, and Grade 8 are available, each offering different levels of strength and durability.
Carbon steel bolts are used in a variety of industries, including construction and automobile.
Alloy Steel
Alloy steel bolts are created by combining particular alloying components with carbon steel to improve mechanical qualities.
Chromium, molybdenum, nickel, and vanadium are common alloying elements used to improve strength, hardness, and corrosion resistance.
Alloy steel bolts are suited for high-stress applications and corrosion-resistant conditions.
Stainless Steel
Chromium is present in stainless steel bolts, which produces a protective oxide coating on the surface, offering good corrosion resistance.
Stainless steel grades (e.g., 304, 316) have varied levels of corrosion resistance and strength.
Stainless steel bolts are frequently employed in applications where moisture or corrosive conditions are present.
Titanium
Titanium bolts are well-known for their high strength-to-weight ratio, resistance to corrosion, and biocompatibility.
They are widely employed in aeronautical, medical, and marine applications where weight savings and resilience to severe environments are critical.
Titanium bolts are more expensive than steel bolts, but they have distinct advantages in some applications.
Brass
Brass bolts are formed of a copper-zinc alloy.
They have good corrosion resistance, electrical conductivity, and an attractive look.
Decorative and non-magnetic applications are common uses for brass bolts.
Aluminum
Aluminum alloy bolts are lightweight and resistant to corrosion.
They are employed in applications that require weight reduction, such as the automobile and aerospace sectors.
Bronze
Bronze bolts are made of a copper-tin alloy that has good corrosion resistance and high strength.
They are frequently employed in marine and architectural applications.
Nickel Alloys
Nickel alloys, such as Inconel and Monel, have strong temperature, corrosion, and stress resistance.
They’re used in harsh environments like aerospace, chemical processing, and marine applications.
Thread Design
The threads on a bolt are meticulously designed to provide a secure grip when paired with a nut. Different thread profiles, such as coarse or fine threads, cater to specific applications.
Head Type
Bolts come in various head types, including hex, square, round, or flange heads. Each serves a specific purpose, offering unique advantages in terms of torque application and accessibility.
Material Composition
The material of a bolt is a critical factor. Common materials include stainless steel, carbon steel, and alloy steel, each chosen based on factors like strength, corrosion resistance, and application requirements.
Coatings and Finishes
Bolts can be coated or finished to enhance their performance and longevity. Options include zinc plating, galvanization, or coatings like Teflon for specific environmental conditions.
Application of Bolts
In the field of architecture. Bolts are used to connect and reinforce building components such as steel structures, bridges, tower cranes, etc., such as steel structures, prefabricated components, concrete, etc.
In the field of transportation. Bolts are used in the manufacturing and maintenance of vehicles such as cars, trains, and airplanes to tighten and connect various components and mechanical components.
In the field of electronics. Bolts are used to secure the casing or circuit board of electronic devices, as well as to connect wire coils and other electronic components.
Home furnishing industry. In the construction of furniture, decoration, and other similar home applications, bolts are commonly used connecting components.
Aerospace field. Bolts are used to fix aircraft structural components, wings, seat belts, and connect automotive components such as engines, transmissions, and wheels.
Head
The head is the topmost part of a bolt. It serves as a gripping surface for the instrument. To tighten or loosen the bolt, a tool with the appropriate bit must hold the head. Most bolts have a head wrench-type.
Shank
There is a conch under the head. The Shank is the smooths part of a bolt that is devoid of threading. It is designed to prevent radial movements of the included workpiece. Without the leg, the bolt is more likely to be loose. Some workpieces produce vibrations, while others are exposed to vibrations in the environment around them.
Threading
All bolts have threading. Threading is one that allows a bolt to move in or out of the workpiece. However, most bolts do not have complete threading. They have ahead, followed by a smooth leg and finally threading. Depending on the type of bolts, the Shank may cover a larger surface area than threading. However, all bolts have threading.
What are the Different Bolts Grades?
Grade 2
The grade 2 bolts are most commonly manufactured from low or medium carbon steel. Bolts of this grade do not have any radial lines. The bolts of this grade with a nominal size range from 1/4″ to 3/4″ have a minimum tensile strength of about 57000 psi and the yield strength of sizes from 3/4″ to 1/2″ 36000 psi.
Grade 5
Unlike grade 2 bolts, grade 5 bolts feature 5 radial lines. These bolts are manufactured from medium carbon steel. These bolts come in two different size ranges – 1/4″ to 1″ and 1″ to 1 1/2″, which have the proof load of 85000 psi and 74000 psi respectively.
Grade 8
Grade 8 bolts are made from medium carbon alloy steel. The bolts of this grade feature 6 radial lines. The nominal size of the grade 8 bolts can be from 1/4″ to 1 1/2″. The minimum yield strength of this grade bolt is 130,000 psi. A maximum of 120,000 psi of tensile force (proof load) can be applied to grade 8 bolts.
Grade S
Grade S bolts have the capability to withstand 45 to 49.9 MT of stress per 6.45 cm3. Bolts of this grade are heavy duty bolts that are strong and highly durable, and thus are used in a variety of heavy duty applications.
Step 1: Selecting Raw Materials
The first step in bolt manufacturing is selecting suitable raw materials. At this stage, bolt manufacturers ensure that the materials comply with global standards, such as ISO or ASTM specifications. High-quality raw material is vital to producing durable and reliable bolts.
Step 2: Wire Drawing
The steel arrives in large coils, which must be refined to the desired thickness. This involves:
● Passing the steel through a series of progressively smaller dies reduces its diameter.
● Enhancing texture quality to prepare for further processing.
Wire drawing ensures that the material is uniform and ready for shaping.
Step 3: Cold Forging (Cold Heading)
Cold forging is the core of the bolt manufacturing process. This step involves:
● Cutting: The wire is cut into pieces of the required length.
● Forming: The cut wire is shaped into the desired bolt head and shank using high-pressure dies.
● Work Hardening: The process improves the steel’s strength by compacting its internal structure.
Cold forging is performed at room temperature, which saves energy and enhances the bolt’s mechanical properties. This process also allows bolt suppliers to produce bolts in large volumes with consistent quality.
Step 4: Thread Rolling or Cutting
Bolts get their signature threads through two main methods:
● Rolling: A preferred method for mass production, where threads are pressed onto the bolt by rolling it between dies.
● Cutting: Used for special bolts requiring precise thread shapes, where material is removed to create the threads.
Threading ensures that the bolts can securely fasten components together, a critical requirement for their functionality.
Step 5: Heat Treatment
Heat treatment strengthens bolts, making them suitable for demanding applications. This process involves:
● Heating the bolts to high temperatures.
● Quenching them in oil or water to harden the steel.
● Tempering to reduce brittleness and improve toughness.
Heat treatment transforms bolts into durable fasteners that can withstand extreme conditions without failure.
Step 6: Surface Finishing
Surface treatments are applied to protect bolts from corrosion and enhance their appearance. Common finishes include:
● Zinc Plating: A popular option for rust resistance.
● Black Oxide Coating: Provides a sleek, matte finish and essential corrosion protection.
● Hot-Dip Galvanizing: Best for heavy-duty bolts exposed to harsh outdoor environments.
At this stage, bolt suppliers ensure the products meet customer specifications for function and aesthetics.
Step 7: Quality Control and Testing
Every bolt undergoes strict quality checks to provide reliability and compliance with standards. Tests include:
● Tensile Strength Testing: Measures the maximum force the bolt can withstand.
● Hardness Testing: Verifies the material’s resistance to deformation.
● Dimensional Accuracy Checks: Ensures that all specifications, such as thread pitch and diameter, are met.
These tests ensure that bolts are safe for critical applications like the construction and automotive industries.
Step 8: Packaging and Distribution
Finally, the bolts are cleaned, lubricated (if necessary), and packaged for shipment. Packaging is crucial to:
● Protect bolts from damage during transport.
● Organize products by size and specification for easy identification.
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