Industrial Fastener · Bolts Series
Heavy Hex Bolt
Heavy hex bolts have a thicker head and larger across-flats dimension than standard hex bolts of the same nominal diameter. The increased bearing surface distributes clamping load more effectively and tolerates higher tightening torque, which is why heavy hex is the standard form for large...
Product Overview
Heavy Hex Bolt sourcing essentials
Heavy hex bolts have a thicker head and larger across-flats dimension than standard hex bolts of the same nominal diameter. The increased bearing surface distributes clamping load more effectively and tolerates higher tightening torque, which is why heavy hex is the standard form for large structural and high-temperature/high-pressure applications.
ASME B18.2.1 heavy series, DIN 6914 (DIN HV)
A307, Grade 5, Grade 8 (inch); 8.8, 10.9 (metric DIN HV)
Heavy hex bolts have a thicker head and larger across-flats dimension than standard hex bolts of the same nominal diameter. The increased bearing...
Inspection records, lot labels, certificate options, and destination-ready packing.
Technical Data
Specification range
Final dimensions, mechanical properties, finish, and packing are confirmed against the RFQ and applicable standard.
| Standards | ASME B18.2.1 heavy series, DIN 6914 (DIN HV) |
|---|---|
| Diameter Range | 1/2" – 3" (M12 – M64 in DIN 6914) |
| Property Class | A307, Grade 5, Grade 8 (inch); 8.8, 10.9 (metric DIN HV) |
| Head Dimensions | Thicker head and larger AF compared to standard hex bolts |
| Surface Finish | Plain, HDG, Zinc plated |
Common surface finishes
Select an option to review its sourcing note. Exact coating system, thickness, and corrosion requirement are confirmed with the order.
Quality Control
Checked before consolidation and export
Each order is matched to the specified standard and verified at practical control points before shipment.
RFQ confirmation
Standard, size, grade, pitch, finish, certificates, packing, and destination are locked before production.
Lot verification
Critical dimensions, thread fit, markings, finish appearance, and packing labels are sampled and recorded.
Shipment approval
Photos and required reports are organized before consolidated loading and export documentation.
Buyer Questions
Frequently asked questions
When is a heavy hex bolt preferred over a standard hex bolt?
Use heavy hex when you need a larger bearing surface under the head (heavy clamping load on a soft or thin mating surface), when high torque is applied during installation, or when local code or specification calls it out. Heavy hex is also standard for many petrochemical and power generation applications.
Are heavy hex bolts the same as heavy hex structural bolts?
No. A heavy hex bolt is a general-purpose bolt with heavy hex head dimensions. A heavy hex structural bolt — typically ASTM A325 or A490 — is a specific high-strength bolt for steel-to-steel structural connections, with shorter thread length and very tight controls on mechanical properties. They look similar but are not interchangeable in structural specifications.
Ready to quote Heavy Hex Bolt?
Send the standard, size, grade, finish, quantity, packing requirement, and destination. Availability and lead time are confirmed with the inquiry.