Standard for Nut

Grade

Hardness

Dimensional style of nut

Nominal nut size

Proof Load Stress                                                    ksi

Head Marking

in.

Non-Zinc coated Nuts

Zinc coated Nuts

SAE J995

2

HRC32 max

hex

1/4 to 1-1/2

90

90

5

HRC32 max

hex

1/4 to 1

120

120

1-1/8 to 1-1/2

105

105

8

24-32HRC

hex

1/4 to 5/8

150

150

26-34HRC

3/4 to 1

26-36HRC

1-1/8 to 1-1/2