SAE J995 covers the mechanical and chemical requirements for inch series nuts in three grades used in automotive and related industries in sizes to 1-1/2” inclusive. SAE J995 Grades 2, 5, and 8 nuts are readily available in a standard hex pattern.
J995 Mechanical Properties
| Grade | Nominal Size, inches | Proofload, UNC and UN 8 Threads, psi | Rockwell Hardness |
|---|
| 2 | 1/4 thru 1-1/2 | 90,000 | C32 Max |
|---|
| 5 | 1/4 thru 1 | 120,000 | C32 Max |
|---|
| Over 1 thru 1-1/2 | 105,000 | C32 Max |
| 8 | 1/4 thru 5/8 | 150,000 | C24-C32 |
|---|
| Over 5/8 thru 1 | 150,000 | C26-C34 |
| Over 1 thru 1-1/2 | 150,000 | C26-C36 |
| *Values listed are not normally applicable to jam, slotted, castle, heavy or thick nuts. |
J995 Chemical Requirements
| Grade | Carbon, % | Phosphorus, % | Manganese, % | Sulfur, % |
|---|
| 2 | 0.47 max | 0.120 max | - | 0.15 max |
|---|
| 5 | 0.55 max | 0.050 max | 0.30 min | 0.15 max |
|---|
| 8 | 0.55 max | 0.040 max | 0.30 min | 0.05 max |
|---|
J995 Tensile Stress Area
| Thread, UNC | UNC Stress Area, sq inches | Thread, 8TPI | 8 TPI Stress Area, sq inches |
|---|
| 1/2-13 | 0.1419 | | |
| 5/8-11 | 0.226 | | |
| 3/4-10 | 0.334 | | |
| 7/8-9 | 0.462 | | |
| 1-8 | 0.606 | 1-8 | 0.606 |
| 1-1/8-7 | 0.763 | 1-1/8-8 | 0.790 |
| 1-1/4-7 | 0.969 | 1-1/4-8 | 1.000 |
| 1-3/8-6 | 1.155 | 1-3/8-8 | 1.233 |
| 1-1/2-6 | 1.405 | 1-1/2-8 | 1.492 |
| To calculate individual nut proofload value, simply multiply the tensile stress area by the appropriate psi proofload value. |
