A563 Grades

A - Carbon steel, hex or heavy hex

B - Carbon steel, hex or heavy hex

C - Carbon steel, quenched and tempered, heavy hex

D - Carbon steel, quenched and tempered, heavy hex

DH - Carbon steel, quenched and tempered, heavy hex

C3 - Weathering steel, quenched and tempered, heavy hex

DH3 - Weathering steel, quenched and tempered, heavy hex


A563 Mechanical Properties
Grade Style Size, in. Plain Galvanized Hardness, HBN
A Hex 1/4" to 1-1/2" 90 68 116 - 302
Heavy Hex 1/4" to 4" 100 75 116 - 302
B Heavy Hex 1/4" to 1" 133 100 121 - 302
Heavy Hex 1-1/8" to 1-1/2" 116 87 121 - 302
C / C3 Heavy Hex 1/4" to 4" 144 144 143 - 352
D Heavy Hex 1/4" to 4" 150 150 248 - 352
DH / DH3 Heavy Hex 1/4" to 4" 175 150 248 - 352

For UNC, 8UN, 6UN, and Coarse Pitch Threads


A563 Chemical Properties
Element 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 0.12% 0.04% 0.04%
Sulfur 0.15%* max 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


Element Classes for Grade C3* DH3
A B C D E F N
Carbon 0.33 - 0.40% 0.38 - 0.48% 0.15 - 0.25% 0.15 - 0.25% 0.20 - 0.25% 0.20 - 0.25% - 0.20 - 0.53%
Manganese 0.90 - 1.20% 0.70 - 0.90% 0.80 - 1.35% 0.40 - 1.20% 0.60 - 1.00% 0.90 - 1.20% - 0.40% min
Phosphorus 0.040% max 0.06 - 0.12% 0.035% max 0.040% max 0.040% max 0.040% max 0.07 - 0.15% 0.046% max
Sulfur, max 0.05% 0.05% 0.04% 0.05% 0.04% 0.04% 0.05% 0.05%
Silicon 0.15 - 0.35% 0.30 - 0.50% 0.15 - 0.35% 0.25 - 0.50% 0.15 - 0.35% 0.15 - 0.35% 0.20 - 0.90% -
Copper 0.25 - 0.45% 0.20 - 0.40% 0.20 - 0.50% 0.30 - 0.50% 0.30 - 0.60% 0.20 - 0.40% 0.25 - 0.55% 0.20% min
Nickel 0.25 - 0.45% 0.50 - 0.80% 0.25 - 0.50% 0.50 - 0.80% 0.30 - 0.60% 0.20 - 0.40% 1.00% max 0.20% min**
Chromium 0.45 - 0.65% 0.50 - 0.75% 0.30 - 0.50% 0.50 - 1.00% 0.60 - 0.90% 0.45 - 0.65% 0.30 - 1.25% 0.45% min
Vanadium - - 0.020% min - - - - -
Molybdenum - 0.06% max - 0.10% max - - - 0.15% min**
Titanium - - - 0.05% max - - - -

* Selection of a class shall be at the option of the manufacturer

** Nickel or Molybdenum may be used.


A563 Grade Identification Markings
Grade Identification Marking Specification Material and Treatment Nominal Size, In. Proof Load Stress, ksi Hardness Rockwell See Note
Min Max
ASTM A563 Grade A B and O ASTM A563 Grade O Carbon Steel 1/4" to 1-1/2" 69 B55 C32 2,3
ASTM A563 Grade A Carbon Steel 1/4" to 1-1/2" 90 B68 C32 2,3
ASTM A563 Grade B Carbon Steel 1/4" to 1" 120 B69 C32 2,3
1-1/8" to 1-1/2" 105
ASTM A563 Grade C ASTM A563 Grade C Carbon Steel, may be Quenched and Tempered 1/4" to 4" 144 B78 C38 4
ASTM A563 Grade C3 ASTM A563 Grade C3 Atmospheric Corrosion Resistant Steel, may be Quenched and Tempered 1/4" to 4" 144 B78 38 4,6
ASTM A563 Grade D ASTM A563 Grade D Carbon Steel, may be Quenched and Tempered 1/4" to 4" 150 B84 C38 5
ASTM A563 Grade DH ASTM A563 Grade DH Carbon Steel, Quenched and Tempered 1/4" to 4" 175 C24 C38 5
ASTM A563 Grade DH3 ASTM A563 Grade DH3 Atmospheric Corrosion Resistant Steel, Quenched and Tempered 1/4" to 4" 175 C24 C38 4,6

NOTES:

  1. In addition to the indicated grade marking, all grades, except A563 grades O, A, and B, must be marked for manufacturer identification.
  2. Nuts are not required to be marked unless specified by the purchaser. When marked, the identification marking shall be the grade letter O, A, or B.
  3. Properties shown are those of nonplated or noncoated coarse thread nuts.
  4. Properties shown are those of coarse thread heavy hex nuts.
  5. Properties shown are those of coarse thread heavy hex nuts. Other nuts styles and fine threads may apply.
  6. The nut manufacturer, at his option, may add other markings to indicate the use of atmospheric corrosion resistant steel.
    Inch Fastener Standards. 7th ed. Cleveland: Industrial Fasteners Institute, 2003. n-80-n-81.

All information derived from globally recognized specifications, subject to change, user discretion is advised.