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 |  |
| 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.