ASME/ANSI B18.2.1 Hex Bolts
ASME B18.2.1 hex bolts specifies the main dimensions and tolerances of hexagon head bolts, including nominal diameter, width across flats, width across corners, head height, body diameter, bolt length, and other related dimensions. These bolts are available with Unified inch threads, including UNC coarse threads and UNF fine threads, and can be supplied with either full or partial threads depending on the bolt size and application. Carbon steel, alloy steel, and stainless steel can be selected according to the required service conditions. Mechanical properties are specified by the applicable material and grade standards, such as SAE J429 Grade 2, Grade 5 and Grade 8, ASTM A307 for carbon steel fasteners, and ASTM F593 for stainless steel fasteners. Surface finishes include zinc plating, hot-dip galvanizing, black oxide, and Dacromet coating, depending on the required corrosion protection. ASME B18.2.1 hex bolts are commonly used for machinery, industrial equipment, manufacturing, maintenance, and general assemblies requiring inch-size fasteners.
Specification:
We manufacture ASME B18.2.1 hex bolts, offering various diameters, lengths and thread specifications. Customers can choose between UNC or UNF threads, as well as full threads or partial threads according to their order requirements. Commonly used materials include carbon steel, alloy steel and stainless steel. Corresponding materials and surface treatments can be provided based on different strength grades and usage environments. We can also produce non-standard lengths and customized sizes according to customer drawings or specific specifications, and conduct size, thread and mechanical performance inspections before shipment.
| Item | Specification |
|---|---|
| Standard | ASME B 18.2.1 |
| Product Type | Hex Head Bolts |
| Size Range | 1/4"-3" |
| Thread | UNC/UNF |
| Thread Type | Full Thread/Partial Thread |
| Thread Standard | ASME B 1.1 |
| Steel Property Grade | SAE J 429 GR.2.5.8 ASTM A193 B7 B16 |
| Stainles Steel Property Grade | F593 C,F593 D, F593 H ASTM A193 B8 ,B8M |
| Material | Carbon Steel, Stainless Steel, Alloy Steel |
| Surface treatment | Black Oxidation,Zinc Plated, Hot Dip Galvanized,Bright Finish,Passivation |
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
- DIN933 HEX BOLTS
- DIN 931 HEX BOLTS
- ISO 4017 HEX BOLTS
- ISO 4014 HEX BOLTS
- ASME B 18.2.1 HEX BOLTS
- HEAVY HEX BOLTS
- DIN 6914 STRUCTURAL BOLTS
- AS 1252 STRUCTURAL BOLTS
- ASME B 18.2.6 HEAVY HEX BOLTS
- JIS 1186 BOLTS
- EN 14399-3 BOLTS
- EN 14399-4 BOLTS
- STUD BOLTS
- DIN976 STUD BOLTS
- DIN939 STUD BOLTS
- ASME B 18.31.2 STUD BOLTS
- IFI 136 STUD BOLTS
Mechanical Property of ASME/ANSI B18.2.1 Hex Bolts:
SAE J 429 Carbon Steel & Alloy Steel Bolts
| 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 |
|---|---|---|---|---|---|---|---|---|
| 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. | ||||||||
ASTM F593 Stainless Steel Bolts
F593C and F593D are produced using austenitic stainless steel 304 or 304L materials. F593C is suitable for specifications ranging from 1/4″ to 5/8″, and F593D is suitable for larger diameter specifications ranging from 3/4″ to 1-1/2″. F593G is suitable for specifications ranging from 1/4″ to 5/8″, and is produced using 316 or 316L materials.
| Mechanical Property Marking | Diameter,in | Full-Size Tests | Machine Specimen Test | ||||
| Tensile Strength (ksi) | Yield Strength (ksi) | Rockwell Hardness | Tensile Strength (ksi) | Yield Strength (ksi) | Elongation in 4D,% | ||
| F593C | 1/4"-5/8" | 100-150 | 65 | B95-C32 | 95 | 60 | 20 |
| F593D | 3/4"-1"-1/2" | 85-140 | 45 | B80-C32 | 80 | 40 | 25 |
| F593C | 1-1/8"-1-1/4" | 100-140 | 60 | B95-C30 | 95 | 55 | 20 |
| F593D | 1-1/8"-1-1/2" | 95-130 | 45 | B90-C28 | 90 | 40 | 28 |
| F593G | 1/4"-5/8" | 100-150 | 65 | B95-C32 | 95 | 60 | 20 |
| F593H | 3/4"-1"-1/2" | 85-140 | 45 | B80-C32 | 80 | 40 | 25 |
| F593G | 1-1/8"-1-1/4" | 100-140 | 60 | B95-C30 | 95 | 55 | 20 |
| F593H | 1-1/8"-1-1/2" | 95-130 | 45 | B90-C28 | 90 | 40 | 28 |
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.