Heavy Hex Bolts
High Strength Heavy Hex Bolts for Steel Structures & Industrial Construction
VALTOR supplies high-strength heavy hex bolts for structural steel connections, industrial buildings and engineering projects. The product focus is ASTM F3125/F3125M Grade A325 and Grade A490. Grade, Type, dimensions, material, heat treatment and finish are confirmed against the contract edition and project requirements.
Product Overview
Heavy Hex Bolts on this page are specified for structural steel connections under ASTM F3125/F3125M, focusing on Grade A325 and Grade A490. These grade names are retained within the consolidated structural bolting specification. The edition designated by the procurement contract and project governs.
A heavy hex head provides a different head geometry from a standard hex head; head style alone does not establish strength, preload or connection capacity. Grade, Type, dimensions, material, heat treatment and inspection must meet the applicable requirements. DIN, ISO and ASTM specifications are not interchangeable.
Heavy hex structural bolts are designed for bolted structural steel connections. Headed anchor bolts are separately specified anchoring components used to connect structural elements or equipment to concrete foundations. Their design, standards and procurement requirements are different.
Technical Specifications
Standard requirements and actual supply availability are distinct. Confirm grade, Type, dimensions and coating as a complete purchasing specification.
Material Options
Carbon steel and alloy steel structural bolting remain the main product scope. Material selection, chemistry, heat treatment and mechanical properties depend on Grade, Type and the governing specification; a raw material description alone does not demonstrate compliance.
Stainless steel heavy hex bolts may be supplied under separately specified material and product requirements. They should not be represented as equivalent to ASTM F3125 Grade A325 or A490 solely based on head style.
Surface Treatment Options
Finish selection follows the bolt grade, governing standard edition and project requirements. Supply methods are subject to project specification and confirmation; the options below do not represent universal processing capability.
Hot-dip or mechanical galvanizing may be specified where permitted by the applicable requirements. Confirm the coating process and complete matched assembly before ordering.
Under the 2025 RCSC Specification, hot-dip and mechanical galvanizing are not permitted for these heavy hex bolts. Do not assume electroplated zinc, metallizing or any zinc-based coating is acceptable. Any alternative coating requires verification against the governing specifications and project approval.
Plain finish is distinct from a coated product. Black appearance does not establish a black oxide treatment, corrosion performance or structural coating compliance; any specified black oxide treatment requires separate confirmation.
Galvanized structural bolting requires compatible nuts and washers, specified nut thread overtapping, lubrication and matched components. Use the same galvanizing process for threaded components. Required rotational capacity testing and documentation must be confirmed for the supplied assembly; ordinary hex nuts or washers are not automatically suitable.
High Strength Structural Bolting Solutions
Provide the ASTM standard and edition, Grade and Type, diameter, under-head length, quantity, finish or coating, matching nut and washer requirements, project application, inspection and documentation requirements, and delivery destination. Include drawings and packaging requirements where relevant.
Bolts, nuts and washers must meet the corresponding component specifications and project requirements as a compatible assembly. Confirm mechanical properties, coating compatibility and required tests; a matching nominal thread size alone is insufficient.
Quality & Documentation
Agree required records, traceability and inspection scope before ordering. Mandatory specification requirements remain applicable; additional third-party inspection, document formats and associated charges require confirmation. These headings are purchasing checkpoints, not a claim that every service is included.
Applications
Heavy hex structural bolts for steel construction and industrial projects.
Heavy hex bolts are widely used for steel frame connections and structural assemblies.
Used in factory buildings, warehouses and large steel structures requiring reliable fastening.
Bridge steel connections where the project specifies the relevant grade, component assembly, coating and inspection requirements.
Bolted steel-to-steel connections in heavy structural assemblies, subject to project design. Concrete foundation anchoring is outside this product description.
Fabricated steel connections using project-specified bolt grades, compatible components and installation requirements.
Frequently Asked Questions
What are heavy hex bolts used for?
The products described here are for specified structural steel connections in buildings, steel fabrication, bridges and heavy structural assemblies, subject to project design and installation requirements.
What is the difference between heavy hex bolts and standard hex bolts?
Heavy hex bolts have different head dimensions, including a larger width across flats for a comparable nominal diameter. Head style alone does not establish a strength grade or connection capacity; check the governing product specification.
What is the difference between ASTM F3125 Grade A325 and A490?
They are distinct structural bolt grades with different material and mechanical requirements. A490 belongs to the higher-strength Group 150; A325 belongs to Group 120. They are not automatically interchangeable. Select the specified grade, Type and compatible assembly for the project.
Can ASTM A325 and A490 bolts be hot-dip galvanized?
Grade A325 may be hot-dip galvanized where the applicable requirements permit. The 2025 RCSC Specification does not permit hot-dip or mechanical galvanizing for Group 150 Grade A490 heavy hex bolts. Confirm coating compatibility and assembly testing before ordering.
Are heavy hex structural bolts the same as anchor bolts?
Heavy hex structural bolts are designed for bolted structural steel connections. Headed anchor bolts are separately specified anchoring components used to connect structural elements or equipment to concrete foundations. Their design, standards and procurement requirements are different.
Are matching nuts and washers required?
Yes. Specify compatible nuts and washers meeting the applicable component and project requirements. Galvanized assemblies also require attention to nut overtapping, lubrication, component matching and necessary rotational capacity testing.
What information should be provided when requesting a quotation?
Provide the ASTM standard and edition, Grade and Type, diameter, under-head length, quantity, finish or coating, matching nut and washer requirements, project application, inspection and documentation requirements, and delivery destination. Include drawings and packaging requirements where relevant.
Can custom sizes and packaging be supplied?
Submit the required dimensions, drawing and packaging for review. Custom supply is subject to confirmation; dimensions outside the governing specification must not be described as automatically compliant with ASTM F3125.
Related Products
Provide the ASTM standard and edition, Grade and Type, diameter, under-head length, quantity, finish or coating, matching nut and washer requirements, project application, inspection and documentation requirements, and delivery destination. Include drawings and packaging requirements where relevant.