ASME B18.2.1 Heavy Hex Bolts
ASME B18.2.1 heavy hex bolts are inch-series fasteners manufactured to the dimensional requirements specified by ASME B18.2.1. The standard defines key dimensions of heavy hex bolts, including head width, head height, body diameter, bolt length and thread length, providing a consistent dimensional basis for applications requiring heavy hex head configurations.
ASME B18.2.1 primarily addresses dimensional requirements rather than material or mechanical performance. Depending on the application, bolts with B18.2.1 dimensions can be supplied with material and mechanical properties specified by applicable standards such as ASTM A193, ASTM A320, ASTM A394 and SAE J429. Thread specifications are based on the applicable Unified inch thread requirements, allowing the bolts to be supplied in different grades, materials and finishes according to project requirements.
Specification:
ASME B18.2.1 defines the dimensional requirements for inch-series heavy hex bolts, including head dimensions, body diameter, bolt length and thread length. The standard provides a common dimensional basis for heavy hex bolts manufactured in different materials and grades. Depending on the application and required mechanical properties, B18.2.1 heavy hex bolts can be supplied in carbon steel, alloy steel and stainless steel, with material, heat treatment and mechanical properties specified by the applicable ASTM, SAE or other material standards.
Thread requirements are specified separately according to the Unified inch screw thread system, while the selected material and grade determine the applicable mechanical and chemical requirements. Common options include carbon steel and alloy steel grades such as ASTM A193 and ASTM A320, as well as stainless steel grades and other material specifications according to customer requirements.
| Item | Specification |
|---|---|
| Standard | ASME B18.2.1 |
| Product Type | Heavy Hex Bolts |
| Size System | Inch |
| Size Range | 3/8"-6" |
| Thread Type | UNC,UNF |
| Thread Standard | ASME B1.1 |
| Thread Tolerance | 2A |
| Material | Carbon Steel,Stainless Steel,Alloy Steel |
| Surface Treatment | Black Oxidation, Zinc Plated,Hot Dip Galvanized,Bright Finish,Passivation |
| Mechanical Proeperty Standard | A320,A193,A394 SAEJ429 |
| Inspection | Dimensions, Thread,Mechanical Property,Coating |
Dimension Chart of ASME B18.2.1 Heavy Hex Bolts:
| Mon | 3/8 | 1/2 | 5/8 | 3/4 | 7/8 | 1 | 1-1/8 | 1-1/4 | 1-3/8 | 1-1/2 | 1-5/8 | 1-3/4 | 1-7/8 | 2 | 2-1/4 | 2-1/2 | 2-3/4 | 3 |
| P | 16 | 13 | 11 | 10 | 9 | 8 | 7 | 7 | 6 | 6 | 6 | 5 | 6 | 4.5 | 4.5 | 4 | 4 | 4 |
| ds max | 0.375 | 0.5 | 0.625 | 0.75 | 0.875 | 1 | 1.125 | 1.25 | 1.375 | 1.5 | 1.625 | 1.75 | 1.875 | 2 | 2.25 | 2.5 | 2.75 | 3 |
| ds min | 0.36 | 0.482 | 0.605 | 0.729 | 0.852 | 0.976 | 1.098 | 1.223 | 1.345 | 1.47 | 1.591 | 1.716 | 1.839 | 1.964 | 2.214 | 2.461 | 2.711 | 2.961 |
| s max | 0.688 | 0.875 | 1.062 | 1.25 | 1.438 | 1.625 | 1.812 | 2 | 2.188 | 2.375 | 2.562 | 2.75 | 2.938 | 3.125 | 3.5 | 3.875 | 4.25 | 4.625 |
| s min | 0.669 | 0.85 | 1.031 | 1.212 | 1.394 | 1.575 | 1.756 | 1.938 | 2.119 | 2.3 | 2.481 | 2.662 | 2.844 | 3.025 | 3.388 | 3.75 | 4.112 | 4.475 |
| e max | 0.794 | 1.01 | 1.227 | 1.443 | 1.66 | 1.876 | 2.093 | 2.309 | 2.526 | 2.742 | 2.959 | 3.175 | 3.392 | 3.608 | 4.041 | 4.474 | 4.907 | 5.34 |
| e min | 0.763 | 0.969 | 1.175 | 1.383 | 1.589 | 1.796 | 2.002 | 2.209 | 2.416 | 2.622 | 2.829 | 3.035 | 3.242 | 3.449 | 3.862 | 4.275 | 4.688 | 5.102 |
| k max | 0.243 | 0.323 | 0.403 | 0.483 | 0.563 | 0.627 | 0.718 | 0.813 | 0.878 | 0.974 | 1.038 | 1.134 | 1.198 | 1.263 | 1.423 | 1.583 | 1.744 | 1.935 |
| k min | 0.226 | 0.302 | 0.378 | 0.455 | 0.531 | 0.591 | 0.658 | 0.749 | 0.81 | 0.902 | 0.962 | 1.054 | 1.114 | 1.175 | 1.327 | 1.479 | 1.632 | 1.815 |
Application of ASME B18.2.1 Heavy Hex Bolts:
Carbon Steel Heavy Hex Bolts
Carbon steel heavy hex bolts are widely used in general industrial equipment, machinery, construction, steel fabrication and mechanical assemblies. They provide a practical fastening solution for applications where reliable strength and cost-effective performance are required. Different carbon steel grades can be selected according to the required mechanical properties and service conditions.
Alloy Steel Heavy Hex Bolts
Alloy steel heavy hex bolts are suitable for demanding applications requiring higher strength, hardness and load-carrying capability. They are commonly used in heavy machinery, industrial equipment, energy facilities, structural assemblies and other applications where enhanced mechanical performance is required. Heat-treated alloy steel grades can be selected according to the specified strength and service requirements.
Stainless Steel Heavy Hex Bolts
Stainless steel heavy hex bolts are designed for applications where corrosion resistance and durability are important. They are commonly used in outdoor equipment, marine environments, chemical processing, food processing, machinery and other applications exposed to moisture or corrosive conditions. Stainless steel grades such as 304 and 316 can be selected according to the service environment.