A563

Standard specification for carbon and alloy steel nuts.

A563

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
DH3 Weathering steel, quenched and tempered, heavy hex

 

Table 1 Chemical Requirement (Compositionm,%)

GRADE / ELEMENTS % 0, A, B, C D ( C ) DH ( C )
Carbon 0.55 max 0.55 max 0.20-0.55
Manganese   0.30 0.60
Phosporous, Max 0.12 0.04 0.04
Sulfur, Max 0.15(A) 0.05 0.05

NOTES: 

(A)For Grades 0, A, and B a sulfur content of 0.23% max is acceptable with the purchasers approval.

(B)Acid bessemer steel only.

(C)For Grades D and DH a sulfur content of 0.05-0.15% is acceptable provided the manganese is 1.35% min.

 

TABLE 2 : CHEMICAL REQUIREMENTS FOR GRADES C3 AND DH3 NUTS

Element / Composition, %

Classes for Grade C3 Nuts (A)

Grade DH3
Nuts

A B C D
Carbon: 0.31-0.42 0.36-0.50 0.14-0.26 0.14-0.26 0.19-0.55
Manganese: 0.86-1.24 0.67-0.93 0.76-1.39 0.36-1.24 0.37 min
Phosphorus: 0.045 max 0.06-0.125 0.040 max 0.045 max 0.052 max
Sulfur: 0.055 max 0.055 max 0.045 max 0.055 max 0.055 max
Silicon: 0.13-0.37 0.25-0.55 0.13-0.37 0.20-0.55  
Copper: 0.22-0.48 0.17-0.43 0.17-0.53 0.27-0.53 0.17 min
Nickel : 0.22-0.48 0.47-0.83 0.22-0.53 0.47-0.83 0.17 min
Chromium: 0.42-0.68 0.47-0.83 0.27-0.53 0.45-1.05 0.42 min
Vanadium:     0.010 min    
Molybdenum:   0.07 max   0.11 max 0.14 min

NOTES:

(A)C3 nuts may be made of any of the above listed material classes. Selection of the class shall be at the option of the manufacturer.

(B)Nickel or molybdenum may be used.

TABLE 3 MECHANICAL REQUIREMENTS

Nuts With UNC, 8 UN, 6 UN and Coarser Pitch Threads

 

Grade of Nut

Nominal Nut
Size, in.

Style of Nut

Proof Load Stress, ksi (A) Hardness

Non-Zinc-Coated
Nuts (B)

Zinc-Coated
Nuts (B)

Brinell Rockwell
min max min max
A 1/4 to 1-1/2 square 90 68 116 302 B68 C32
A 1/4 to 1-1/2 hex 90 68 116 302 B68 32
B 1/4 to 1 hex 120 90 121 302 B69 32
B 1-1/8 to 1-1/2 hex 105 79 121 302 B69 C32
D (C) 1/4 to 1-1/2 hex 135 135 159 352 B84 C38
DH (D) 1/4 to 1-1/2 hex 150 150 248 352 C24 C38
DH3 1/2 to 1 hex 150 150 248 352 C24 C38
A 1/4 to 4 heavy hex 100 75 116 302 B68 C32
B 1/4 to 1 heavy hex 133 100 121 302 B69 C32
B 1-1/8 to 1-1/2 heavy hex 116 87 121 302 B69 32
C3 1/4 to 4 heavy hex 144 144 143 352 B78 C38
D (C) 1/4 to 4 heavy hex 150 150 159 352 B84 C38
DH (D) 1/4 to 4 heavy hex 175 150 248 352 C24 C38
DH3 1/4 to 4 heavy hex 175 150 248 352 C24 C38
A 1/4 to 1-1/2 hex thick 100 75 116 302 B68 C32
B 1-1/4 to 1 hex thick 133 100 121 302 B69 C32
B 1-1/8 to 1-1/2 hex thick 116 87 121 302 B69 32
D (C) 1/4 to 1-1/2 hex thick 150 150 159 352 B84 38
DH (D) 1/4 to 1-1/2 hex thick 175 175 248 352 C24 C38

Nuts with UNF, 12 UN, and Finer Pitch Threads

A 1/4 to 1-1/2 hex 80 60 116 302 B68 C32
B 1/4 to 1 hex 109 82 121 302 B69 C32
B 1-1/8 to 1-1/2 hex 94 70 121 302 B69 32
D (C) 1/4 to 1-1/2 hex 135 135 159 352 B84 38
DH (D) 1/4 to 1-1/2 hex 150 150 248 352 C24 C38
A 1/4 to 4 heavy hex 90 68 116 302 B68 32
B 1/4 to 1 heavy hex 120 90 121 302 B69 C32
B 1-1/8 to 1-1/2 heavy hex 105 79 121 302 B69 C32
D (C) 1/4 to 4 heavy hex 150 150 159 352 B84 C38
DH (D) 1/4 to 4 heavy hex 175 150 248 352 C24 C38
A 1/4 to 1-1/2 hex thick 90 68 116 302 B68 C32
B 1/4 to 1 hex thick 120 90 121 302 B69 C32
B 1-1/8 to 1-1/2 hex thick 105 79 121 302 B69 32
D (C) 1/4 to 1-1/2 hex thick 150 150 159 352 B84 38
DH (D) 1/4 to 1-1/2 hex thick 175 175 248 352 C24 C38


(A)To determine nut proof load in pounds, multiply the appropriate nut proof load stress by the tensile stress area of the thread.NOTES:

(B)Non-zinc-coated nuts are nuts intended for use with externally threaded fasteners which have a plain (nonplated or noncoated) 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 A 194/A 194M, Grade 2 or Grade 2H, and marked with their grade symbol are acceptable equivalents for Grades C and D nuts. When A 194 zinc-coated inch series nuts are supplied, the zinc coating, overtapping, lubrication and rotational capacity testing shall be in accordance with Specification A 563.

(D)Nuts made in accordance with the requirements of Specification A 194/A 194M, Grade 2 H, and marked with its grade symbol are an acceptable equivalent for Grade DH nuts. When A 194 zinc-coated inch series nuts are supplied, the zinc coating, overtapping, lubrication and rotational capacity testing shall be in accordance with Specification A 563.

TABLE X1.1

NUT AND BOLT SUITABILITY GUIDE

A563 Grade and ANSI Nut Style (A)

Grade of Bolt Surface Finish Nominal Recommended (B) Suitable ( C )
( D ) ( E ) Size in. Hex Heavy Hex Square Hex Heavy Hex Hex Thick
A 307

non-zinc- coated and Zinc Coated

1/4 to 1 1/2 A A B, D, DH A,B,C,D,DH,DH3 A,B,D,DH
  >1 1/2 to 2 A A(F) C,D,DH,DH3
Grade A >2 to 4 A C,D,DH,DH3
A 307

non-zinc- coated and Zinc Coated

1/4 to 1 1/2 A A B, D, DH B,C,D,DH,DH3 A,B,D,DH
  >1 1/2 to 2 A A(F) C,D,DH,DH3
Grade B >2 to 4 A C,D,DH,DH3
A 325 non-zinc- coated 1/2 to 1 1/2 C C,D,DH,DH3
Type 1 Zinc Coated 1/2 to 1 1/2 DH
A 325 Type 3 non-zinc- coated 1/2 to 1 1/2 C3 DH3

A 354

non-zinc- coated

1/4 to 1 1/2 C D, DH C3,D,DH,DH3 D, DH
>1 1/2 to 4 C C3,D,DH,DH3

Grade BC

Zinc Coated

1/4 to 1 1/2 DH DH
>1 1/2 to 4 DH

A 354 Grade BD

non-zinc- coated

1/4 to 1 1/2 DH DH D,DH,DH3 D, DH
>1 1/2 to 4 DH DH3
A 394 Type O Zinc- coated 1/2 to 1 A B,D
A 394 Type 1 and 2 Zinc- coated 1/2 to 1 DH D
A 394 Type 3 non zinc- coated 1/2 to 1 DH3 C3

A 449

non-zinc- coated

1/4 to 1 1/2 B D, DH B,C,C3,D,DH,DH3 B, D, DH
>1 1/2 to 3 A C3,D,DH,DH3

Type 1 and 2

Zinc Coated

1/4 to 1 1/2 DH D, DH D D, DH
>1 1/2 to 3 DH D
A 490 Type 1 and 2 non-zinc- coated 1/2 to 1 1/2 DH DH3
A 490 Type 3 non-zinc- coated 1/2 to 1 1/2 DH3
A 687 non-zinc- coated 1 1/4 to 3 D DH,DH3
  Zinc Coated 1 1/4 to 3 DH

Notes :

(A)The availability of DH nuts in nominal sizes 3/4 in. and larger is very limited and generally available only on special orders for 50 000 pieces or more. For smaller quantities A 194 Gr. 2H nuts should be considered.

(B)"Recommended" denotes a commercially available nut having the most suitable mechanical properties and dimensional configuration (style) that will make it possible to torque the bolt to the required load when used in combination with the nut.

(C)"Suitable" denotes nuts having mechanical properties that will make it possible to torque the bolt to the required load when used in combination with the nut; but, which require consideration of dimensional configuration (style) suitability and availability. Others are not suitable.

(D)The term "bolt" includes all externally threaded types of fasteners.

(E)Non-zinc-coated nuts are nuts intended for use with externally threaded fasteners which have a plain (nonplated or noncoated) finish or have a plating or coating of insufficient thickness to necessitate overlapping 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 overlapping the nut thread to provide assemblability.

(F)Hex nuts in nominal sizes over 11/2 to 2 in. inclusive are not covered in the tables of tabulated sizes in ANSI B18.2.2 but are commercially available. Such nuts are suitable. See 7.2 for dimensions.