SAE J429

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 of 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
2 1/4 thru 3/4 55,000 57,000 74,000 18 35 B80 to B100 N/A
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 sae-grade-5
8 Medium Carbon Alloy Steel 0.28 - 0.55 0.030 max 0.050 max sae-grade-8

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".