Tensile Strength of a Grade 5 Bolt
| Value | 827,000,000 Pa |
| Status | Conventional / typical value |
| Source | SAE J429 / Machinery's Handbook, 31st ed. |
| Categories | Material PropertiesEngineering & Trademechanics |
| pascal | 827,000,000 Pa |
| kilopascal | 827,000 kPa |
| megapascal | 827 MPa |
| bar | 8,270 bar |
| atmosphere | 8,161.8554 atm |
| millimeter of mercury | 6,203,009.2 mmHg |
| pound per square inch | 119,946.21 psi |
| foot of water column | 276,674.97 ft H₂O |
| gigapascal | 0.827 GPa |
| kip per square inch | 119.94621 ksi |
| inch of mercury | 244,212.96 inHg |
| inch of water column | 3,320,099.7 in w.g. |
Learning zone
SAE Grade 5 — the three-radial-line head marking, medium carbon steel quenched and tempered — is the common automotive and machinery fastener: 120 ksi minimum tensile, 92 ksi yield, 85 ksi proof. Proof strength is the number that matters for preload, because it is the stress the bolt can carry with no measurable permanent set; standard practice targets 75 % of proof for reusable joints and up to 90 % for single-use.
Note that all of these are stresses, and the area they act on is the tensile stress area, not the shank area — a 1/2-13 bolt has 0.1419 in² of stress area against 0.196 in² of shank, so using the nominal diameter overstates capacity by nearly 40 %. Above 1 in diameter Grade 5 drops to 105 ksi tensile, and metric property class 8.8 is the near equivalent (800 MPa tensile, 640 MPa yield). Structural steelwork uses a different family entirely — ASTM F3125 Grade A325 and A490 — and the grades are not interchangeable with SAE fasteners.