Scope

SAE J429 covers the mechanical and material requirements for inch series fasteners used in automotive and related industries in sizes to 1-1/2” inclusive.

Below is a basic summary the most common grades. SAE J429 covers a number of other grades and grade variations not covered in this summary, including 4, 5.1, 5.2, 8.1, and 8.2.

J429 Mechanical Properties

Grade

Nominal Size, inches

Full Size Proofload,
psi

Yield Strength, min,
psi

Tensile Strength, min, psi

Elong, min,
%

RA, min,
%

Core Hardness, Rockwell

Tempering Temperature, min

1

1/4 thru 1-1/2

33,000

36,000

60,000

18

35

B7 to B100

N/A

1/4 thru 3/4

55,000

57,000

74,000

18

35

B80 to B100

N/A

2

Over 3/4 thru 1-1/2

33,000

36,000

60,000

18

35

B70 to B100

5

1/4 thru 1

85,000

92,000

120,000

14

35

C25 to C34

800F

Over 1 thru 1-1/2

74,000

81,000

105,000

14

35

C19 to C30

8

1/4 thru 1-1/2

120,000

130,000

150,000

12

35

C33 to C39

800F

Grade 2 requirements for sizes 1/4″ thru 3/4″ apply only to bolts 6″ and shorter, and to studs of all lengths. For bolts longer than 6″, Grade 1 requirements shall apply.

J429 Chemical Requirements

Grade

Material

Carbon, %

Phosphorus, %

Sulfur, %

Grade Marking

1

Low or Medium Carbon Steel

0.55 max

0.030 max

0.050 max

None

2

Low or Medium Carbon Steel

0.15 – 0.55

0.030 max

0.050 max

None

5

Medium Carbon Steel

0.28 – 0.55

0.030 max

0.050 max

8

Medium Carbon Alloy Steel

0.28 – 0.55

0.030 max

0.050 max

J429 Recommended Hardware

Nuts

Washers

J995

N/A

Alternate Grades

For fasteners larger than 1-1/2″ in diameter, the following ASTM grades should be considered.

SAE J429 Grade

ASTM Equivalent

Grade 1

A307 Grades A or B

Grade 2

A307 Grades A or B

Grade 5

A449

Grade 8

A354 Grade BD

This chart compares SAE and ASTM specifications that are similar but not identical in diameters through 1½”.