Hex bolts
ASME B18.2.1 – Hex bolts, inch
ASME B18.2.1. Dimensions from the HBS technical datasheet – in stock, with EN 10204 3.1 / 3.2 certificates.
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From stock at HBS
Hex bolts to ASME B18.2.1: from stock, with EN 10204 3.1 / 3.2 certificates and a quote within 24 hours.
Dimensions
ASME B18.2.1 dimension table.
Dimensions in inches
| Nominal size | Basic diameter | Body dia. E | Width across flats F | Across corners G | Head height H | Fillet R | Thread length LT | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| max. | min. | basic | max. | min. | max. | min. | basic | max. | min. | max. | min. | L ≤ 6" | L > 6" | ||
| 1/4" | 0.2500 | 0.26 | 0.237 | 7/16 | 0.438 | 0.425 | 0.505 | 0.484 | 11/64 | 0.188 | 0.15 | 0.03 | 0.01 | 0.750 | 1.000 |
| 5/16" | 0.3125 | 0.324 | 0.298 | 1/2 | 0.5 | 0.484 | 0.577 | 0.552 | 7/32 | 0.235 | 0.195 | 0.03 | 0.01 | 0.875 | 1.125 |
| 3/8" | 0.3750 | 0.388 | 0.36 | 9/16 | 0.562 | 0.544 | 0.65 | 0.62 | 1/4 | 0.268 | 0.226 | 0.03 | 0.01 | 1.000 | 1.250 |
| 7/16" | 0.4375 | 0.452 | 0.421 | 5/8 | 0.625 | 0.603 | 0.722 | 0.687 | 19/64 | 0.316 | 0.272 | 0.03 | 0.01 | 1.125 | 1.375 |
| 1/2" | 0.5000 | 0.515 | 0.482 | 3/4 | 0.75 | 0.725 | 0.866 | 0.826 | 11/32 | 0.364 | 0.302 | 0.03 | 0.01 | 1.250 | 1.500 |
| 5/8" | 0.6250 | 0.642 | 0.605 | 15/16 | 0.938 | 0.906 | 1.083 | 1.033 | 27/64 | 0.444 | 0.378 | 0.06 | 0.02 | 1.500 | 1.750 |
| 3/4" | 0.7500 | 0.768 | 0.729 | 1-1/8 | 1.125 | 1.088 | 1.299 | 1.24 | 1/2 | 0.524 | 0.455 | 0.06 | 0.02 | 1.750 | 2.000 |
| 7/8" | 0.8750 | 0.895 | 0.852 | 1-5/16 | 1.312 | 1.269 | 1.516 | 1.447 | 37/64 | 0.604 | 0.531 | 0.06 | 0.02 | 2.000 | 2.250 |
| 1" | 1.0000 | 1.022 | 0.976 | 1-1/2 | 1.5 | 1.45 | 1.732 | 1.653 | 43/64 | 0.7 | 0.591 | 0.09 | 0.03 | 2.250 | 2.500 |
| 1-1/8" | 1.1250 | 1.149 | 1.098 | 1-11/16 | 1.688 | 1.631 | 1.949 | 1.859 | 3/4 | 0.78 | 0.658 | 0.09 | 0.03 | 2.500 | 2.750 |
| 1-1/4" | 1.2500 | 1.277 | 1.223 | 1-7/8 | 1.875 | 1.812 | 2.165 | 2.066 | 27/32 | 0.876 | 0.749 | 0.09 | 0.03 | 2.750 | 3.000 |
| 1-3/8" | 1.3750 | 1.404 | 1.345 | 2-1/16 | 2.062 | 1.994 | 2.382 | 2.273 | 29/32 | 0.94 | 0.81 | 0.09 | 0.03 | 3.000 | 3.250 |
| 1-1/2" | 1.5000 | 1.531 | 1.47 | 2-1/4 | 2.25 | 2.175 | 2.598 | 2.48 | 1 | 1.036 | 0.902 | 0.09 | 0.03 | 3.250 | 3.500 |
| 1-5/8" | 1.6250 | 1.658 | 1.591 | 2-7/16 | 2.438 | 2.356 | 2.815 | – | 1-3/32 | 1.116 | 0.978 | 0.09 | 0.03 | 3.500 | 3.750 |
| 1-3/4" | 1.7500 | 1.785 | 1.716 | 2-5/8 | 2.625 | 2.538 | 3.031 | 2.893 | 1-5/32 | 1.196 | 1.054 | 0.12 | 0.04 | 3.750 | 4.000 |
| 1-7/8" | 1.8750 | 1.912 | 1.839 | 2-13/16 | 2.812 | 2.719 | 3.248 | 3.099 | 1-1/4 | 1.276 | 1.13 | 0.12 | 0.04 | 4.000 | 4.250 |
| 2" | 2.000 | 2.039 | 1.964 | 3 | 3 | 2.9 | 3.464 | 3.306 | 1-11/32 | 1.388 | 1.175 | 0.12 | 0.04 | 4.250 | 4.500 |
| 2-1/4" | 2.2500 | 2.305 | 2.214 | 3-3/8 | 3.375 | 3.262 | 3.897 | 3.719 | 1-1/2 | 1.548 | 1.327 | 0.19 | 0.06 | 4.750 | 5.000 |
| 2-1/2" | 2.5000 | 2.559 | 2.461 | 3-3/4 | 3.75 | 3.625 | 4.33 | 4.133 | 1-21/32 | 1.708 | 1.479 | 0.19 | 0.06 | 5.250 | 5.500 |
| 2-3/4" | 2.7500 | 2.827 | 2.711 | 4-1/8 | 4.125 | 3.988 | 4.763 | 4.546 | 1-13/16 | 1.869 | 1.632 | 0.19 | 0.06 | 5.750 | 6.000 |
| 3" | 3.000 | 3.081 | 2.961 | 4-1/2 | 4.5 | 4.35 | 5.196 | 4.959 | 2 | 2.06 | 1.815 | 0.19 | 0.06 | 6.250 | 6.500 |
| 3-1/4" | 3.2500 | 3.335 | 3.21 | 4-7/8 | 4.875 | 4.712 | 5.629 | 5.372 | 2-3/16 | 2.251 | 1.936 | 0.19 | 0.06 | 6.750 | 7.000 |
| 3-1/2" | 3.5000 | 3.589 | 3.461 | 5-1/4 | 5.25 | 5.075 | 6.062 | 5.786 | 2-5/16 | 2.38 | 2.057 | 0.19 | 0.06 | 7.250 | 7.500 |
| 3-3/4" | 3.7500 | 3.858 | 3.726 | 5-5/8 | 5.625 | 5.437 | 6.495 | 6.198 | 2-1/2 | 2.572 | 2.241 | 0.19 | 0.06 | 7.750 | 8.000 |
| 4" | 4.000 | 4.111 | 3.975 | 6 | 6 | 5.8 | 6.928 | 6.612 | 2-11/16 | 2.764 | 2.424 | 0.19 | 0.06 | 8.250 | 8.500 |
- E
- Body diameter
- F
- Width across flats
- G
- Width across corners
- H
- Head height
- R
- Fillet radius
- LT
- Thread length
Grades and finishes: hbsfasteners.nl/products/hex-bolts.
FAQ
ASME B18.2.1 – frequently asked questions.
- What is ASME B18.2.1?
- ASME B18.2.1 is the standard for hex bolts, inch (ASME B18.2.1). HBS Solutions supplies ASME B18.2.1 hex bolts from stock, with EN 10204 3.1 / 3.2 certificates.
- Which sizes does ASME B18.2.1 cover?
- The HBS datasheet lists ASME B18.2.1 from 1/4" to 4". The full dimension table is on this page and in the free PDF datasheet.
- How do I order ASME B18.2.1 hex bolts?
- Configure the part online or send your parts list through the quote form; HBS Solutions replies with a quotation within 24 hours. Stock items ship from 500.000+ pieces in stock in Almere, the Netherlands.
Related standards
Related standards.
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