ASTM A563-07a

Scope
1.1 This specification covers 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.

1.3 Grades C3 and DH3 nuts have atmospheric corrosion resistance and weathering characteristics comparable to that of the steels covered in Specifications A242, A588 & A709. The atmospheric corrosion resistance of these steels is substantially better than that of carbon steel with or without copper addition. When properly exposed to the atmosphere, these steels can be used bare (uncoated) for many applications.

Table 1: Chemical Requirements for Grades O, A, B, C, D and DH Nuts

GradeAnalysisCarbonManganese, minPhophorus, maxSulfur, max
O,A,B,CHeat0.55 max-0.120.15 ᴬ
Product0.58 max-0.13 ᴮ-
D ᶜHeat0.55 max0.30.040.05
Product0.58 max0.270.0480.058
DH ᶜHeat0.20-0.550.60.040.05
Product0.18-0.580.570.0480.058
Source: ASTM A563-07a

Table 2: Chemical Requirements for Grades C3 and DH3 Nuts

ElementAnalysisClasses for Grade C3 Nuts ᴬGrade
NABCDEFDH3 Nuts
CarbonHeat-0.33 - 0.400.38 - 0.480.15 - 0.250.15 - 0.250.20 - 0.250.20 - 0.250.20 - 0.53
Product-0.31 - 0.420.36 - 0.500.14 - 0.260.14 - 0.260.18 - 0.270.19 - 0.260.19 - 0.55
ManganeseHeat-0.90 - 1.200.70 - 0.900.80 - 1.350.40 - 1.200.60 - 1.000.90 - 1.200.40 min
Product-0.86 - 1.240.67 - 0.930.76 - 1.390.36 - 1.240.56 - 1.040.86 - 1.240.37 min
PhosphorusHeat0.07 - 0.150.040 max0.06 - 0.120.035 max0.040 max0.040 max0.040 max0.046 max
Product0.07 - 0.1550.045 max0.06 - 0.1250.040 max0.045 max0.045 max0.045 max0.052 max
SulfurHeat0.050 max0.050 max0.050 max0.040 max0.050 max0.040 max0.040 max0.050 max
Product0.055 max0.055 max0.055 max0.045 max0.055 max0.045 max0.045 max0.055 max
SiliconHeat0.20 - 0.900.15 - 0.350.30 - 0.500.15 - 0.350.25 - 0.500.15 - 0.350.15 - 0.35-
Product0.15 - 0.950.13 - 0.370.13 - 0.370.13 - 0.370.20 - 0.550.13 - 0.370.13 - 0.37-
CopperHeat0.25 - 0.550.25 - 0.450.20 - 0.400.20 - 0.50 0.30 - 0.500.30 - 0.600.20 - 0.400.20 min
Product0.22 - 0.580.22 - 0.480.17 - 0.430.17 - 0.530.27 - 0.530.27 - 0.630.17 - 0.430.17 min
NickelHeat1.00 max0.25 - 0.450.50 - 0.800.25 - 0.500.50 - 0.800.30 - 0.600.45 - 0.650.20 min ᴮ
Product1.03 max0.22 - 0.480.47 - 0.830.22 - 0.530.47 - 0.830.27 - 0.630.42 0.680.17 min
ChromiumHeat0.30 - 1.250.45 - 0.650.50 - 0.750.30 - 0.500.50 - 1.000.60 - 0.900.45 - 0.650.45 min
Product0.25 - 1.300.52 - 0.680.74 - 0.830.27 - 0.530.45 -1.050.55 - 0.950.42 - 0.680.42 min
VanadiumHeat---0.020 min----
Product---0.010 min----
MolybdenumHeat--0.06 max-0.10 max--0.15 min ᴮ
Product--0.07 max-0.11 max--0.14 min
TitaniumHeat----0.05 max---
Product--------
Source: ASTM A563

Table 3 Mechanical Requirements for Nuts with UNC & 8 UN Threads

Grade of NutNominal SizeStyleProof Load Stress, ksi ᴬBrinell HardnessRockwell Hardness
Non Zinc Coated ᴮZinc Coated ᴮminmaxminmax
O1/4" to 1-1/2"Hex6952103302B55C32
A1/4" to 1-1/2"Hex9068116302B68C32
B1/4" to 1"Hex12090121302B69C32
B1-1/8" to 1-1/2"Hex10579121302B69C32
D ᶜ1/4" to 1-1/2"Hex135135159352B84C38
DH ᴰ1/4" to 1-1/2"Hex150150248352C24C38
DH31/2" to 1"Hex150150248352C24C38
A1/4" to 4" Heavy Hex10075116302B68C32
B1/4" to 1"Heavy Hex133100121302B69C32
B1-1/8" to 1-1/2"Heavy Hex11687121302B69C32
C ᶜ1/4" to 4" Heavy Hex144144143352B78C38
C31/4" to 4" Heavy Hex144144143352B78C38
D ᶜ1/4" to 4" Heavy Hex150150159352B84C38
DH ᴰ1/4" to 4" Heavy Hex175150248352C24C38
DH31/4" to 4" Heavy Hex175150248352C24C38
Source: ASTM A563-07a

A: To determine nut proof load in pounds, multiply the appropriate nut proof load stress by the tensile stress area of the thread. Stress areas for UNC  and 8 UN thread series are given in Table 4.
B: Non-zinc-coated nuts are nuts intended for use with externally threaded fasteners which have a plain (non-plated or non-coated) finish or have a plating or coating of insufficient thickness to necessitate overtapping the nut thread to provide assemblability. Zinc-coated nuts are nuts intended for use with externally threaded fasteners which are hot-dip zinc-coated, mechanically zinc-coated, or have a plating or coating of sufficient thickness to necessitate overtapping the nut thread to provide assemblability.
C: Nuts made in accordance to the requirements of Specification A194, Grade 2 or Grade 2H, and marked with their grade symbol are acceptable equivalents for Grades C and D nuts. When A194 zinc-coated inch series nuts are supplied, the zinc coating, overtapping, lubrication and rotational capacity testing shall be in accordance with Specification A563.
D: Nuts made in accordance with the requirements of Specification A194, Grade 2H, and marked with its grade symbol are an acceptable equivalent for Grade DH nuts. When A194 zinc-coated inch series nuts are supplied, the zinc coating, overtapping, lubrication and rotational capacity testing shall be in accordance with Specification A563.

Table 4 Tensile Stress Areas

UNC8 UN
Nominal Dia.Threads per InchTensile Stress Area, ᴬ in.₂Nominal Dia.Threads per InchTensile Stress Area, ᴬ in.₂
1/4"200.0318---
5/16"180.0524---
3/8"160.0775---
7/16"140.1063---
1/2"130.1419---
9/16"120.182---
5/8"110.226---
3/4"100.334---
7/8"90.462---
1"80.6061"80.606
1-1/8"70.7631-1/8"80.79
1-1/4"70.9691-1/4"81
1-3/8"61.1551-3/8"81.233
1-1/2"61.4051-1/2"81.492
1-3/4"51.91-3/4"82.08
2"4.52.52"82.77
2-1/4"4.53.252-1/4"83.56
2-1/2"442-1/2"84.44
2-3/4"44.932-3/4"85.43
3"45.973"86.51
3-1/4"47.13-1/4"87.69
3-1/2"48.333-1/2"88.96
3-3/4"49.663-3/4"810.34
4"411.084"811.81
Source: ASTM A563-07a

As The stress area is calculated as follows: As = 0.7854 [D –0.9743/n]²
where:
As = stress area, in.²,
D = nominal size, in., and
n = threads per inch.

Table 5 Thread Dimensions and Overtapping Allowances for Nuts Hot Dip Zinc Coated per F2329

Nominal Nut Size, in.Threads per InchDiametral Allowance, in. ᴬPitch Diameter, in
minmax
0.25200.0160.23350.2384
0.312180.0170.29340.2987
0.375160.0170.35140.3571
0.437140.0180.40910.4152
0.5130.0180.4680.4745
0.562120.020.52840.5352
0.625110.020.5860.5932
0.75100.020.7050.7127
0.87590.0220.82480.833
180.0240.94280.9516
1.12580.0241.06781.0768
1.12570.0241.05621.0656
1.2580.0241.19281.202
1.2570.0241.18121.1908
1.37580.0271.32081.3301
1.37560.0271.29371.3041
1.580.0271.44581.4553
1.560.02741.41871.4292
1.7550.051.67011.6817
24.50.051.90571.9181
2.254.50.052.15572.1683
2.540.052.38762.4011
2.7540.052.63762.6513
340.052.88762.9015
3.32540.053.13763.1517
3.540.053.38763.4019
3.7540.053.63763.6521
3.7540.053.63763.6521
440.053.88763.9023
Source: ASTM A563-07a

A – These allowances also apply to the minimum and maximum major and minor diameters.

Table X1.1 Nut Compatibility Chart

Grade of BoltFinishNominal SizeA563 Grade and ANSI Nut Style
RecommendedSuitable
HexHeavy HexHexHeavy Hex
A307 Grade A & CAny1/4 to 1-1/2A-B,D,DHA,B,C,D,DH,DH3
A307 Grade A & CAny>1-1/2 to 2-AAC,D,DH,DH3
A307 Grade A & CAny>2 to 4-A-C,D,DH,DH3
A307 Grade BAny1/4 to 1-1/2-AB,D,DH B,C,D,DH,DH3
A307 Grade BAny>1-1/2 to 2-AA-
A307 Grade BAny>2 to 4-A--
A325 Type 1Plain1/2 - 1-1/2-C-C3, D, DH, DH3
A325 Type 1Galvanized1/2 - 1-1/2-DH--
A325 Type 3Plain1/2 - 1-1/2-C3-DH3
A354 Grade BCPlain1/4 to 1-1/2-C-C3, D, DH, DH3
A354 Grade BCPlain>1-1/2 to 4-C-C3, D, DH, DH3
A354 Grade BCGalvanized1/4 to 1-1/2-DH--
A354 Grade BCGalvanized>1-1/2 to 4-DH--
A354 Grade BDPlain1/4 to 1-1/2-DH-D, DH, DH3
A354 Grade BDPlain>1-1/2 to 4-DH-DH3
A449Plain1/4 to 1-1/2B-D, DHB,C,D,DH,DH3
A449Plain>1-1/2 to 3-A-C,C3,D,DH,DH3
A449Galvanized1/4 to 1-1/2-DHD, DHD
A449Galvanized>1-1/2 to 3-DH-D
A490 Type 1Plain1/2 - 1-1/2-DH-DH3
A490 Type 3Plain1/2 - 1-1/2-DH3--
A687Plain5/8 - 3-DH-DH, DH3
A687Galvanized5/8 - 3-DH3--
F1554 Grade 55Plain1/4 to 1-1/2A-B,D,DH A,B,C,D,DH,DH3
F1554 Grade 55Plain>1-1/2 to 4-A-C,D,DH,DH3
F1554 Grade 55Galvanized1/4 to 4-A-C,D,DH,DH3
F1554 Grade 105Plain1/4 to 1-1/2D--DH, DH3
F1554 Grade 105Plain>1-1/2 to 3-DH-DH3
F1554 Grade 105Galvanized1/4 to 3-DH-DH3
Source: ASTM A563-07a Appendix X1

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