⬇️ Bearing Stress

Written and maintained by the PhDino author · Last reviewed 21 September 2026 · A documented rule of thumb, pinned by automated tests · how PhDino checks its numbers

Related standards: AISC 360

The contact pressure where one surface presses directly against another, and the safety factor against crushing.

When a load is transferred through direct surface contact — a beam resting on a plate, a pin in a hole, a column base on a footing — the contact pressure is called bearing stress. Unlike tension or shear failure of a member itself, bearing failure is local crushing or excessive deformation right at the contact surface.

Different materials have very different allowable bearing stresses; concrete and wood, being much softer than steel, are usually the limiting material in a steel-on-concrete or steel-on-wood bearing connection.

Key formula

σ_bearing = P / A_bearing

Variables

P

load transferred through the bearing surface

A_bearing

actual contact area

Notes & limitations

• Bearing area is the actual contact footprint, not the full cross-sectional area of either part — get this wrong and the stress estimate is wrong by whatever factor the areas differ.
• For concrete bearing specifically, ACI 318 allows a higher bearing stress when the loaded area is small relative to the supporting concrete area (confinement effect) — a refinement not included in this simplified check.