Nut Compatibility Chart

Grade of Bolt Surface Finish Nominal Size Inches A563 Grade and ANSI Nut Style
Recommended Suitable
Hex Heavy Hex Hex Heavy Hex
A307 Grade A & C
 Any 1⁄4 to 11⁄2
A
B,D,DH
A,B,C,D,DH,DH3
>11⁄2 to 2
A
A
C,D,DH,DH3
>2 to 4
A
C,D,DH,DH3
A307 Grade B
 Any 1⁄4 to 11⁄2
A
B,D,DH
A,B,C,D,DH,DH3
>11⁄2 to 2
A
A
>2 to 4
A
F3125 A325 Type 1
 Plain 1⁄2 - 11⁄2
C
C3,D,DH,DH3
Galvanized 1⁄2 - 11⁄2
DH
F3125 A325 Type 3
 Plain 1⁄2 - 11⁄2
C3
DH3
A354 Grade BC
 Plain 1⁄4 to 11⁄2
C
D,DH
C3,D,DH,DH3
>11⁄2 to 4
C
C3,D,DH,DH3
Galvanized 1⁄4 to 11⁄2
DH
>11⁄2 to 4
DH
A354 Grade BD
 Plain 1⁄4 to 11⁄2
DH
DH
D,DH,DH3
>11⁄2 to 4
DH
DH3
A449
 Plain 1⁄4 to 11⁄2
B
D,DH
B,C,C3,D,DH,DH3
>11⁄2 to 3
A
C,C3,D,DH,DH3
Galvanized 1⁄4 to 11⁄2
DH
D,DH
D
>11⁄2 to 3
DH
D
F3125 A490 Type 1
 Plain 1⁄2 - 11⁄2
DH
DH3
F3125 A490 Type 3
 Plain 1⁄2 - 11⁄2
DH3
A687
 Plain 5⁄8 - 3
D
DH,DH3
Galvanized 5⁄8 - 3
DH
F1554 Grade 36
 Any 1⁄2 to 11⁄2
A
B,D,DH
A,B,C,D,DH,DH3
>11⁄2 to 4
A
C,D,DH,DH3
F1554 Grade 55
 Plain 1⁄2 to 11⁄2
A
B,D,DH
A,B,C,D,DH,DH3
>11⁄2 to 4
A
C,D,DH,DH3
Galvanized 1⁄2 to 4
A
C,D,DH,DH3
F1554 Grade 105
 Plain 1⁄2 to 11⁄2
D
DH,DH3
>11⁄2 to 3
DH
DH3
Galvanized 1⁄2 to 3
DH
DH3
1. 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. (per ASTM A563/A563M-21a, Table X1.1)

ASTM A194 Nut Compatibility Chart

Grade of Bolt A194 Heavy Hex Nut Grade
A193 Grade B7 2H or 4 or 7
A193 Grade B8 (Class 1 and 2) 8
A193 Grade B8M (Class 1 and 2) 8M
A320 Grade L7 4 or 7
A320 Grade B8 (Class 1 and 2) 8
A320 Grade B8M (Class 1 and 2) 8M
A320 Grade B8C 8C
A320 Grade B8T 8T
A320 Grade B8LN 8LN
A320 Grade B8MLN 8MLN
For Class 2 stainless steel grades, strain hardened nuts available as a supplementary requirement