Heavy Hex Bolts

Heavy hex bolts are structural fasteners with a larger head and thicker shank than standard hex bolts, designed for high-strength connections in heavy-duty industrial environments. At Zhejiang Chance & Union Import and Export Co., Ltd., we manufacture heavy hex bolts in carbon steel, alloy steel, and stainless steel grades, meeting ASTM A325, A490, and DIN 6914 specifications. Our production capacity and testing protocols ensure consistent mechanical properties for bolting applications that demand reliability under high torque and vibration.

Core Advantages

Material range: Available in Grade 5, Grade 8, B7, L7, and 316 stainless steel, with customized coatings including hot-dip galvanizing, zinc plating, and Xylan.
Precise dimensional control: Threads rolled to Class 2A tolerance, with head dimensions per ASME B18.2.1; flat bearing surface reduces embedment.
High-strength grades: Tensile strength up to 150 ksi (for alloy steel quenched and tempered), suitable for preloaded bolting assemblies.
Traceability: Each batch receives material test reports (MTR) and heat numbers, enabling full lifecycle documentation.

Product Characteristics

Parameter	Specification / Range
Diameter range	Available in imperial (inch) and metric sizes; common diameters from 1/2 inch to 2-1/2 inch (M12 to M64), other sizes upon request
Length range	Standard lengths from 1-1/4 inch up to 12 inch; custom lengths manufactured per order
Thread class	2A (UNC/UNF) for imperial; 6g for metric threads
Materials	Carbon steel (Gr.5, Gr.8), Alloy steel (B7, L7), Stainless steel (304, 316, 410)
Finish options	Plain, zinc plated, hot-dip galvanized, phosphate, Dacromet, Xylan
Hardness (HRC)	Range depends on grade and heat treatment; typically between 25 and 35 HRC for quenched and tempered grades

Specific dimensions and mechanical properties are defined per ASTM A325 / A490 or DIN 6914; contact our team for detailed datasheets.

Application Scenarios

Structural steel connections: Bridges, high-rise buildings, stadiums, and transmission towers.
Heavy machinery: Mining equipment, earthmoving machinery, and press frames.
Wind energy: Turbine tower flange bolting and blade root connections.
Marine and offshore: Corrosion-resistant grades for deck fittings, subsea flanges.
Automotive jigs & fixtures: High-cycle fatigue applications with controlled tightening.

R&D & Production Capabilities

With nearly 20 years of fastener engineering experience, our R&D team has developed over 1,000 custom fastener solutions for 200+ industrial clients worldwide. We invest in material analysis, thread rolling optimization, and coating performance testing. Our 30,000 m² facility houses 80+ multi-station cold headers and automated machining centers, enabling monthly output of 800 tons. We support just-in-time delivery with lead times from 7 to 25 days for volume orders.

Testing & quality: Optical sorting for 100% dimensional inspection; 72-hour salt spray test per ASTM B117; tensile and hardness testing per ASTM E8 and E18; ISO 9001 and IATF 16949 certified processes.
Warehousing & logistics: Permanent stock of 5,000+ specifications, capacity exceeding 2,000 tons. 24-hour order processing and 3-day rapid shipping for standard items.

Frequently Asked Questions (FAQ)

What is the difference between heavy hex bolts and standard hex bolts?

Heavy hex bolts have a larger head width and height, and a thicker shank (body) compared to standard hex bolts. This provides a larger bearing surface and higher clamp load capacity, making them suitable for structural and high-strength connections. They also have a wider wrenching surface for greater torque application.

Which materials and coatings are available for heavy hex bolts?

We supply heavy hex bolts in carbon steel (Grade 5, Grade 8), alloy steel (B7, L7), and stainless steel (304, 316, 410). Coatings include plain, zinc plating, hot-dip galvanizing (HDG), phosphate, Dacromet, and Xylan. Selection depends on environmental exposure and required corrosion resistance.

How do you ensure quality and traceability for heavy hex bolts?

Each batch is accompanied by material test reports (MTR) with heat numbers. We perform 100% optical sorting for dimensional accuracy, plus destructive tensile and hardness tests per batch. Our ISO 9001 and IATF 16949 systems ensure full traceability from raw material to finished product.

What is your typical lead time and minimum order quantity?

For standard heavy hex bolts in stock, we ship within 3 days. For custom sizes or materials, lead time is 7–25 days depending on quantity and coating. MOQ is flexible; we support sample orders and small-batch prototyping.

Company Profile

Fastening Chances, Strengthening Union

Zhejiang Chance & Union Import and Export Co., Ltd. (abbreviated as Chance & Union) is a family-owned China Heavy Hex Bolts company under SEA Monies Metal Co., Ltd., inheriting 20 years of family experience and quality heritage in metal manufacturing. Relying on Shengzhao Metal's strong production capacity and supply chain advantages, we specialize in the R&D, production and global sales of high-quality metal products. Adhering to the family's pursuit of precision, rigorous working attitude and long-term commitment, we deliver stable and reliable products and services to customers across the globe.

Leveraging the factory's robust R&D and production capabilities, we specialize in high-strength rivets bolts, nuts, washers, pins, screws, and various non-standard custom parts. As experienced Custom Heavy Hex Bolts Suppliers, we provide flexible manufacturing solutions for different customer requirements. Our product range covers materials including stainless steel, alloy steel, aluminum alloy, copper, and special alloys, utilizing processes such as cold heading, hot forging, and CNC machining. Our products are exported to over 25 countries, serving more than 200 clients.

Chance & Union is committed to seamlessly connecting "Manufactured in China" with the international market, providing global customers with one-stop fastening solutions from R&D to mass production through professional technology and exceptional quality.