Shear Modulus of Structural Steel
| Value | 7.72e10 Pa |
| Status | Measured: ± 1,000,000,000 Pa (0.013 relative) |
| Source | AISC Steel Construction Manual, 15th ed. |
| Categories | Material PropertiesEngineering & Trade |
| microbar | 772,000,000,000 μbar |
| barye | 772,000,000,000 Ba |
| millitorr | 579,047,620,000 mTorr |
| pascal | 77,200,000,000 Pa |
| millimeter of water column | 7,872,209,200 mmH₂O |
| pound per square foot | 1,612,355,500 lb/ft² |
| centimeter of water column | 787,220,920 cmH₂O |
| hectopascal | 772,000,000 hPa |
| millibar | 772,000,000 mbar |
| torr | 579,047,620 Torr |
| millimeter of mercury | 579,047,540 mmHg |
| inch of water column | 309,929,500 in w.g. |
| kilopascal | 77,200,000 kPa |
| foot of water column | 25,827,458 ft H₂O |
| inch of mercury | 22,797,147 inHg |
| pound per square inch | 11,196,913 psi |
| meter of water column | 7,872,209.2 m H₂O |
| decibar | 7,720,000 dbar |
| kilogram-force per square centimeter | 787,220.92 kgf/cm² |
| bar | 772,000 bar |
| atmosphere | 761,904.76 atm |
| megapascal | 77,200 MPa |
| kip per square inch | 11,196.913 ksi |
| gigapascal | 77.2 GPa |
| million pounds per square inch | 11.196913 Mpsi |
Learning zone
Shear modulus is not an independent measurement for an isotropic material: G = E / [2(1 + ν)]. With E = 200 GPa and ν = 0.30 that gives 76.9 GPa, and AISC rounds the design value to 11 200 ksi (77.2 GPa). It is the stiffness that governs angle of twist in a shaft, torsional buckling of an open section, and the shear component of deep-beam deflection.
Two traps. First, the same grade-independence as E applies — a Grade 8 shaft twists exactly as much as a mild-steel one of the same geometry under the same torque, it just survives more of it. Second, torsional stiffness is dominated by the section, not the material: a closed tube is orders of magnitude stiffer in torsion than an open channel or wide-flange of the same weight, because the torsional constant J for an open section is a thin-strip approximation that collapses with wall thickness cubed. If a member has to resist torsion, change the shape before you change the steel.