Atlanta Rod & Manufacturing is a premier American manufacturer of domestic heavy hex bolts, structural headed bolts, and custom high-strength fasteners. Produced directly at our state-of-the-art facility in Lavonia, Georgia, all our heavy hex headed bolts meet 100% Build America, Buy America (BABA) Act and American Iron and Steel (AIS) domestic compliance mandates. Every order is fully traceable with certified domestic Mill Test Reports (MTRs) documenting melt-and-manufacture origin in the United States.
Heavy Hex Bolt Dimensions & ASME B18.2.1 Specifications
Heavy hex bolts feature a larger head profile and wider bearing area than standard finished hex bolts, distributing clamping loads over a greater surface to prevent flange embedment and withstand extreme structural loads. Manufactured in strict conformance to ASME B18.2.1 standards, our domestic manufacturing range spans from 3/8” to 3” diameters (and up to 4” on custom runs) in standard unified coarse (UNC) and 8-thread series (8UN).
| Nominal Diameter (in) | Body Diameter Max (in) | Width Across Flats F (in) | Width Across Corners G (in) | Head Height H (in) | Thread Pitch (TPI UNC / 8UN) |
|---|---|---|---|---|---|
| 1/2" (0.500) | 0.515 | 7/8 (0.875) | 0.992 | 11/32 (0.344) | 13 UNC |
| 5/8" (0.625) | 0.642 | 1-1/16 (1.062) | 1.205 | 27/64 (0.422) | 11 UNC |
| 3/4" (0.750) | 0.768 | 1-1/4 (1.250) | 1.418 | 1/2 (0.500) | 10 UNC |
| 7/8" (0.875) | 0.895 | 1-7/16 (1.438) | 1.631 | 37/64 (0.578) | 9 UNC |
| 1" (1.000) | 1.022 | 1-5/8 (1.625) | 1.844 | 43/64 (0.672) | 8 UNC / 8UN |
| 1-1/8" (1.125) | 1.149 | 1-13/16 (1.812) | 2.057 | 3/4 (0.750) | 7 UNC / 8UN |
| 1-1/4" (1.250) | 1.277 | 2" (2.000) | 2.270 | 27/32 (0.844) | 7 UNC / 8UN |
| 1-3/8" (1.375) | 1.404 | 2-3/16 (2.188) | 2.483 | 29/32 (0.906) | 6 UNC / 8UN |
| 1-1/2" (1.500) | 1.531 | 2-3/8 (2.375) | 2.696 | 1" (1.000) | 6 UNC / 8UN |
| 1-3/4" (1.750) | 1.789 | 2-3/4 (2.750) | 3.122 | 1-5/32 (1.156) | 5 UNC / 8UN |
| 2" (2.000) | 2.044 | 3-1/8 (3.125) | 3.548 | 1-11/32 (1.344) | 4.5 UNC / 8UN |
| 2-1/2" (2.500) | 2.554 | 3-7/8 (3.875) | 4.399 | 1-21/32 (1.656) | 4 UNC / 8UN |
| 3" (3.000) | 3.064 | 4-5/8 (4.625) | 5.251 | 2" (2.000) | 4 UNC / 8UN |
Domestic Heavy Hex Bolts & High-Strength Material Grades
Atlanta Rod hot-forges and machines heavy hex bolts in a full spectrum of carbon, alloy, and stainless materials engineered to withstand severe pressure, elevated temperatures, and corrosive environmental service. Common specifications include:
| ASTM Specification | Grade / Material | Tensile Strength, min (psi) | Yield Strength, min (psi) | Hardness | Core Structural Applications |
|---|---|---|---|---|---|
| ASTM A307 | Grade B (Flanged) | 60,000 – 100,000 | N/A (Reference) | 69 – 95 HRB | Cast iron flanges, municipal water piping, low-pressure piping |
| ASTM A193 | Grade B7 Alloy Steel | 125,000 (≤ 2-1/2”) | 105,000 (≤ 2-1/2”) | 321 HBW max | High-pressure valves, pressure vessels, petroleum refineries |
| ASTM A193 | Grade B8 / B8M (Class 1 & 2) | 75,000 – 125,000 | 30,000 – 100,000 | 90 HRB – 35 HRC | Marine infrastructure, wastewater plants, chemical processing |
| ASTM A354 | Grade BC Alloy Steel | 125,000 (≤ 2-1/2”) | 109,000 (≤ 2-1/2”) | 255 – 321 HBW | Heavy structural steel, bridges, anchor assemblies |
| ASTM A354 | Grade BD Alloy Steel | 150,000 (≤ 2-1/2”) | 130,000 (≤ 2-1/2”) | 302 – 371 HBW | Severe tensile load connections, heavy crane rails, industrial towers |
| ASTM A453 | Grade 660 (Class A/B) | 130,000 | 85,000 | 24 – 37 HRC | High-temperature bolting up to 1300°F, steam turbines, manifolds |
Precision Rolled Threads & ASTM Fastener Manufacturing
Unlike cut threads that tear through steel fibers and introduce micro-fissures at the thread root, Atlanta Rod specializes in manufacturing heavy hex bolts with precision rolled threads. Thread rolling cold-forms the continuous metallurgical grain flow of the bar stock, increasing yield strength, improving surface finish, and providing 20% to 30% higher fatigue resistance under dynamic cyclic stress. Our in-house thread rolling equipment accommodates standard unified national coarse (UNC), unified fine (UNF), and continuous 8UN thread series up to 3” diameter.
Georgia Construction Fasteners & Infrastructure Applications
As the premier manufacturing source for Georgia construction fasteners and nationwide heavy civil infrastructure projects, Atlanta Rod supplies general contractors, DOT agencies, energy utilities, and marine developers. Whether your job calls for domestic bolts in heavy civil bridges, deep foundation embeds, water treatment facilities, or industrial petrochemical refineries, our Georgia facility provides fast lead times, emergency turnaround runs, and full metallurgical verification.
Build America Buy America (BABA) & AIS Domestic Certification
Federal and state funded infrastructure projects require strict adherence to domestic procurement legislation. Atlanta Rod manufactures 100% melted and manufactured in USA heavy hex bolts compliant with:
- Build America, Buy America (BABA) Act: Fully compliant domestic fastener sourcing for all federally assisted infrastructure programs.
- American Iron and Steel (AIS) Mandate: 100% US melted steel and domestic forging for clean water and drinking water State Revolving Fund projects.
- Complete Mill Test Reports (MTRs): Full physical and chemical submittals provided with every heat lot shipped.
Related High-Spec Fasteners & Alloy Bolting
Explore our complete manufacturing line of domestic fasteners and specialty alloy headed products:
- Explore our standard standard finished hex bolts for standard clearance construction applications.
- Source corrosion-resistant domestic stainless steel fasteners in grades 304, 316, and high-temp alloys.
- Review engineering specifications for high-strength ASTM A354 BC bolts for structural steel embeds.
- View certified corrosion-resistant ASTM A193 B8M bolts and high-temperature ASTM A193 bolts.
- Specify extreme-environment nickel alloy bolting, including Inconel 600 bolts and marine-grade Monel bolts.
Ready to place an order or request submittal specs? Call our engineering sales desk today at 800-633-9794 or email Sales@ATLROD.com for immediate pricing and custom production schedules.