Hex Nut Grade Identification and Mechanical Properties


Grade
Identification
Marking
Specification Material Nominal Size
In.
Proof
Load
Stress
ksi
Hardness
Rockwell
See
Note
Min Max

No Mark
ASTM A563 – Grade 0 Carbon Steel 1/4 thru 1-1/2 69 B55 C32 3,4
ASTM A563 – Grade A Carbon Steel 1/4 thru 1-1/2 90 B68 C32 3,4
ASTM A563 – Grade B Carbon Steel 1/4 thru 1 120 B69 C32 3,4
over 1 thru 1-1/2 105
ASTM A563 – Grade C Carbon Steel
May be Quenched
and Tampered
1/4 thru 4 144 B78 C38 5
ASTM A563 – Grade C3 Atmospheric
Corrosion
Resistant Steel
May be Quenched
and Tampered
1/4 thru 4 144 B78 C38 5,9
ASTM A563 – Grade D Carbon Steel
May be Quenched
and Tampered
1/4 thru 4 150 B84 C38 6
ASTM A563 – Grade DH Carbon Steel
Quenched
and Tampered
1/4 thru 4 175 C24 C38 6
ASTM A563 – Grade DH3 Atmospheric
Corrosion
Resistant Steel,
Quenched
and Tampered
1/4 thru 4 175 C24 C38 5,9
ASTM A194 – Grade 1 Carbon Steel 1/4 thru 4 130 B70 7
ASTM A194 – Grade 2 Medium Carbon
Steel
1/4 thru 4 150 159 352 7,8
ASTM A194 – Grade 2H Medium Carbon
Steel, Quenched
and Tempered
1/4 thru 4 175 C24 C38 7
ASTM A194 – Grade 2HM Medium Carbon
Steel, Quenched
and Tempered
1/4 thru 4 150 159 237 7,8
ASTM A194 – Grade 4 Medium Carbon
Alloy Steel,
Quenched
and Tempered
1/4 thru 4 175 C24 C38 7
ASTM A194 – Grade 7 Medium Carbon
Alloy Steel,
Quenched
and Tempered
1/4 thru 4 175 C24 C38 7
ASTM A194 – Grade 7M Medium Carbon
Alloy Steel,
Quenched
and Tempered
1/4 thru 4 150 159 237 7
See Note 1,2 10

Hex Nut Dimensions


Size Across Flats* Height
Hex Nut Machine Screw Nut Hex Nut Jam Nut Nylock Nut Machine Screw Nut
0 5/32 3/64
1 5/32 3/64
2 3/16 9/64 1/16
3 3/16 9/64 1/16
4 1/4 9/64 3/32
6 5/16 11/64 7/64
8 11/32 15/64 1/8
10 3/8 15/64 1/8
12 7/16 5/16 5/32
1/4 7/16 7/16 7/32 5/32 5/16 3/16
5/16 1/2 9/16 17/64 3/16 11/32 7/32
3/8 9/16 5/8 21/64 7/32 29/64 1/4
7/16 11/16 3/8 1/4 29/64
1/2 3/4 7/16 5/16 19/32
9/16 7/8 31/64 5/16 41/64
5/8 15/16 35/64 3/8 3/4
3/4 1-1/8 41/64 27/64 7/8
7/8 1-5/16 3/4 31/64 63/64
1 1-1/2 55/64 35/64 1-3/64
* This is also the size of wrench to use.