ASME/ANSI B18.2.1 Half Thread Hex Bolts
ASME/ANSI B18.2.1 Half Thread Hex Bolts are manufactured according to the dimensional requirements of ASME/ANSI B18.2.1, which defines the standard dimensions for hex head bolts, including head dimensions, thread length, and overall bolt configuration. As a widely used dimensional standard in the United States, it allows customers to select suitable bolt specifications based on their application requirements.
Our Half Thread Hex Bolts are available in various material grades and strength classes, including SAE Grade 2, Grade 5, and Grade 8, as well as stainless steel options when required. Different surface finishes such as plain finish, zinc plating, hot dip galvanizing, and other protective coatings can be supplied to meet different corrosion resistance and application requirements. With a wide range of sizes and configurations available, we support industrial customers with reliable and flexible fastening solutions.
Specification:
The bolts can be supplied with different material grades according to specific application requirements. ASME/ANSI B18.2.1 Half Thread Hex Bolts are available with various surface finishes, including plain finish, zinc plated, hot dip galvanized. These finishes help improve corrosion resistance and provide suitable solutions for different industrial environments. Customized sizes, thread requirements, and special specifications can also be supplied based on customer drawings or project requirements.
| Product name | ASME B 18.2.1 HEX BOLT |
|---|---|
| Diameter | 1/4"-4" |
| Length | Up to 30" |
| Thread | UNC/UNF |
| Head Type | Hex Head |
| Grade | SAEJ429 GR.2/5/8 A307 A193 B7 |
| Material | Carbon Steel, Stainless Steel, Alloy Steel, Brass |
| Manufacturing Process | wire drawing, cold heading/hot forging, thread rolling, heat treatment, surface treatment |
| Surface treatment | Black Oxide Coating/Zinc Plating /Hot-Dip Galvanizing/Mechanical Galvanizing/Dacromet Coating |
Chemical Composition:
Material selection, including chemical composition and mechanical performance, can be controlled according to applicable standards and customer specifications.
| Grade | Carbon, % | Phosphorus, % | Manganese, % | Sulfur, % |
|---|---|---|---|---|
| 2 | 0.47 max | 0.120 max | - | 0.15 max |
| 5 | 0.55 max | 0.050 max | 0.30 min | 0.15 max |
| 8 | 0.55 max | 0.040 max | 0.30 min | 0.05 max |
Mechanical properties:
Common strength grades include SAE Grade 2, Grade 5, and Grade 8 carbon steel options, as well as stainless steel materials such as ASTM A2-70 and A4-80 when corrosion resistance is required.
| GRADE | Nominal Size, inches | Full Size Proofload, psi | Yield Strength, min, psi | Tensile Strength, min, psi | Elong, min, % | RA, min, % | Core Hardness, Rockwell | Tempering Temperature, min |
|---|---|---|---|---|---|---|---|---|
| 1 | 1/4 thru 1-1/2 | 33,000 | 36,000 | 60,000 | 18 | 35 | B7 to B100 | N/A |
| 2 | 1/4 thru 3/4 | 55000 | 57000 | 74000 | 18 | 35 | B80-B100 | N/A |
| Over 3/4 thru 1-1/2 | 33,000 | 36,000 | 60,000 | 18 | 35 | B70 to B100 | ||
| 5 | 1/4 thru 1 | 85,000 | 92,000 | 120,000 | 14 | 35 | C25 to C34 | 800F |
| Over 1 thru 1-1/2 | 74,000 | 81,000 | 105,000 | 14 | 35 | C19 to C30 | ||
| 8 | 1/4 thru 1-1/2 | 120,000 | 130,000 | 150,000 | 12 | 35 | C33 to C39 | 800F |
| Grade 2 requirements for sizes 1/4" thru 3/4" apply only to bolts 6" and shorter, and to studs of all lengths. For bolts longer than 6", Grade 1 requirements shall apply. | ||||||||
ASME/ANSI B18.2.1 Half Thread Hex Bolts Dimensions:
| Mon | 1/4 | 5/16 | 3/8 | 7/16 | 1/2 | 9/16 | 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 | 20|28|32 | 18|24|32 | 16|24|32 | 14|20|28 | 13|20|28 | 12|18|24 | 11|18|24 | 10|16|20 | 9|14|20 | 8|12|20 | 7|12|18 | 7|12|18 | 6|12|18 | 6|12|18 | 12|18 | 5|8|12 | 6 | 4.5 | 4.5 | 4 | 4 | 4 |
| ds max | 0.25 | 0.3125 | 0.375 | 0.4375 | 0.5 | 0.5625 | 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 | 0.245 | 0.3065 | 0.369 | 0.4305 | 0.493 | 0.5545 | 0.617 | 0.741 | 0.866 | 0.99 | 1.114 | 1.239 | 1.363 | 1.488 | 1.613 | 1.738 | 1.863 | 1.988 | 2.238 | 2.488 | 2.738 | 2.988 |
| s max | 0.438 | 0.5 | 0.562 | 0.625 | 0.75 | 0.812 | 0.938 | 1.125 | 1.312 | 1.5 | 1.688 | 1.875 | 2.062 | 2.25 | 2.438 | 2.625 | 2.812 | 3 | 3.375 | 3.75 | 4.125 | 4.5 |
| s min | 0.428 | 0.489 | 0.551 | 0.612 | 0.736 | 0.798 | 0.922 | 1.1 | 1.285 | 1.469 | 1.631 | 1.812 | 1.994 | 2.175 | 2.356 | 2.538 | 2.719 | 2.9 | 3.262 | 3.625 | 3.988 | 4.35 |
| e max | 0.505 | 0.577 | 0.65 | 0.722 | 0.866 | 0.938 | 1.083 | 1.299 | 1.516 | 1.732 | 1.949 | 2.165 | 2.382 | 2.598 | 2.815 | 3.031 | 3.248 | 3.464 | 3.897 | 4.33 | 4.763 | 5.196 |
| e min | 0.488 | 0.557 | 0.628 | 0.698 | 0.84 | 0.91 | 1.051 | 1.254 | 1.465 | 1.675 | 1.859 | 2.066 | 2.273 | 2.48 | 2.686 | 2.893 | 3.099 | 3.306 | 3.719 | 4.133 | 4.546 | 4.959 |
| k max | 0.163 | 0.211 | 0.243 | 0.291 | 0.323 | 0.371 | 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 | 0.15 | 0.195 | 0.226 | 0.272 | 0.302 | 0.348 | 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 |
- RELATED BOLTS LISTS:
- HEX BOLTS
- HEAVY HEX BOLTS
- DIN931 HEX BOLTS
- AS1252 HEX BOLTS
- DIN6914 HEX BOLTS
- ASME B 18.2.1 HEX BOLTS
- A325 HEAVY HEX BOLTS
- A490 HEAVY HEX BOLTS
- RELATED NUTS LIST:
- HEX NUTS
- HEAVY HEX NUTS
- ISO4032 HEX NUTS
- DIN934 HEX NUTS
- A194 HEAVY HEX NUTS
- A563 HEAVY HEX NUTS
- THREADED ROD LIST:
- DIN975 THREADED RODS
- A193 B7 STUD BOLTS
Applications of ASME/ANSI B18.2.1 Half Thread Hex Bolts:
ASME/ANSI B18.2.1 Half Thread Hex Bolts are widely used in industrial applications where standardized inch dimensions, reliable fastening performance, and flexible material options are required. The partially threaded design provides an unthreaded grip section that can improve clamping stability and is suitable for applications requiring stronger shear resistance and accurate component alignment.
These hex bolts are commonly used in machinery assembly, industrial equipment installation, steel fabrication, agricultural equipment, transportation systems, power facilities, and general manufacturing applications. With various strength grades, materials, and surface finishes available, ASME/ANSI B18.2.1 Half Thread Hex Bolts provide versatile fastening solutions for OEM manufacturers, distributors, contractors, and maintenance teams.