ASTM A563 Specifications
Technical Menu Posted on July 1st, 2015 by vaproThe specification for ASTM A563 covers the chemical and mechanical requirements for eight grades of carbon and alloy steel nuts for general structural and mechanical uses on bolts, studs, and other externally threaded parts. The requirements for any grade of nut may, at the supplier’s option, and with notice to the purchaser, be fulfilled by furnishing nuts of one of the stronger grades specified herein unless such substitution is barred in the inquiry and purchase order.
| Grades | |
|---|---|
| A | Carbon steel, hex or hvy hex |
| B | Carbon steel, hex or hvy hex |
| C | Carbon steel, quenched and tempered, hvy hex |
| D | Carbon steel, quenched and tempered, hvy hex |
| DH | Carbon steel, quenched and tempered, hvy hex |
| C3 | Weathering steel, quenched and tempered, hvy hex |
| DH3 | Weathering steel, quenched and tempered, hvy hex |
Chemical Properties
| Elements | Grades O, A, B, C | D | DH |
|---|---|---|---|
| Carbon | 0.55% max | 0.55% max | 0.20 – 0.55% |
| Manganese, min | 0.30% | 0.60% | |
| Phosphorus, max | 0.12% | 0.04% | 0.04% |
| Sulfur, max | 0.15%* | 0.05% | 0.05% |
| * For grades O, A and B a sulfur content of 0.23% max is acceptable with the purchasers approval | |||
| ** For grades D and DH a sulfur content of 0.05 – 0.15% is acceptable provided the manganese is 1.35% min | |||
Mechanical Properties
| Grade | Style | Size, in. | Proof Load, ksi | Hardness, HBN | |
|---|---|---|---|---|---|
| Plain | Galvanized | ||||
| A | Hex | 1/4 – 1-1/2 | 90 | 68 | 116 – 302 |
| Heavy Hex | 1/4 – 4 | 100 | 75 | 116 – 302 | |
| B | Heavy Hex | 1/4 – 1 | 133 | 100 | 121 – 302 |
| Heavy Hex | 1-1/8 – 1- 1/2 | 116 | 87 | 121 – 302 | |
| C / C3 | Heavy Hex | 1/4 – 4 | 144 | 144 | 143 – 352 |
| D | Heavy Hex | 1/4 – 4 | 150 | 150 | 248 – 352 |
| DH / DH3 | Heavy Hex | 1/4 – 4 | 175 | 150 | 248 – 352 |
Grade Identification Markings
| Marking | Specification | Material Type | Nominal Sizes, In. | Proof Load Stress, ksi | Hardness Rockwell | See Note | |
|---|---|---|---|---|---|---|---|
| Min | Max | ||||||
| No Marking | ASTM A563 Grade O | Carbon Steel | 1/4 – 1-1/2 | 69 | B55 | C32 | 2,3 |
| ASTM A563 Grade A | Carbon Steel | 1/4 – 1-1/2 | 90 | B68 | C32 | 2,3 | |
| ASTM A563 Grade B | Carbon Steel | 1/4 – 1 | 120 | B69 | C32 | 2,3 | |
| >1 – 1-1/2 | 105 | ||||||
| 3 curved lines | ASTM A563 Grade C | Carbon Steel, may be Quenched and Tempered | 1/4 – 4 | 144 | B78 | C38 | 4 |
| 3, with curved lines | ASTM A563 Grade C3 | Atmospheric Corrosion Resistant Steel, may be Quenched and Tempered | 1/4 – 4 | 144 | B78 | 38 | 4,6 |
| D | ASTM A563 Grade D | Carbon Steel, may be Quenched and Tempered | 1/4 – 4 | 150 | B84 | C38 | 5 |
| DH | ASTM A563 Grade DH | Carbon Steel, Quenched and Tempered | 1/4 – 4 | 175 | C24 | C38 | 5 |
| DH3 | ASTM A563 Grade DH3 | Atmospheric Corrosion Resistant Steel, Quenched and Tempered | 1/4 – 4 | 175 | C24 | C38 | 4,6 |
* Nuts made to the requirements of Grades O, A and B are not required to be marked unless individual marking is specified in the inquiry and order. When individual marking is required, the mark shall be the grade letter symbol on one face of the nut *
Thread Dimensions and Overtapping Allowances for Hot Dip Zinc Coated Nuts per Specification A153, C1. C
| Nominal Nut Size, in. and Pitch | Diametral Allowance, in. | Pitch Diameter, in. | |
|---|---|---|---|
| Minimum | Maximum | ||
| 0.250 – 20 | 0.016 | 0.2335 | 0.2384 |
| 0.312 – 18 | 0.017 | 0.2934 | 0.2987 |
| 0.375 – 16 | 0.017 | 0.3514 | 0.3571 |
| 10.437 – 14 | 0.018 | 0.4091 | 0.4152 |
| 0.500 – 13 | 0.018 | 0.4680 | 0.4745 |
| 0.0562 – 12 | 0.020 | 0.5284 | 0.5352 |
| 0.625 – 11 | 0.020 | 0.5860 | 0.5932 |
| 0.750 – 10 | 0.020 | 0.7050 | 0.7127 |
| 0.875 – 9 | 0.022 | 0.8248 | 0.8330 |
| 1.000 – 8 | 0.024 | 0.9428 | 0.9516 |
| 1.125 – 8 | 0.024 | 1.0678 | 1.0768 |
| 1.125 – 7 | 0.024 | 1.0562 | 1.0656 |
| 1.250 – 8 | 0.024 | 1.1928 | 1.2020 |
| 1.250 – 7 | 0.024 | 1.1812 | 1.1908 |
| 1.375 – 8 | 0.027 | 1.3208 | 1.3301 |
| 1.375 – 6 | 0.027 | 1.2937 | 1.3041 |
| 1.500 – 8 | 0.027 | 1.4458 | 1.4553 |
| 1.500 – 6 | 0.027 | 1.4187 | 1.4292 |
| 1.750 – 5 | 0.050 | 1.6701 | 1.6817 |
| 2.000 – 4.5 | 0.050 | 1.9057 | 1.9181 |
| 2.250 – 4.5 | 0.050 | 2.1557 | 2.1683 |
| 2.500 – 4 | 0.050 | 2.3876 | 2.4011 |
| 2.750 – 4 | 0.050 | 2.6376 | 2.6513 |
| 3.000 – 4 | 0.050 | 2.8876 | 2.9015 |
| 3.250 – 4 | 0.050 | 3.1376 | 3.1517 |
| 3.500 – 4 | 0.050 | 3.3876 | 3.4019 |
| 3.750 – 4 | 0.050 | 3.6376 | 3.6521 |
| 4.000 – 4 | 0.050 | 3.8876 | 3.9023 |
Related: ASTM A563 Specifications on ASTM.org
