What is stress in engineering?

Stress is the internal force per unit area within a material. It measures how much force the material's cross-section must resist. The basic formula is σ = F/A, where F is force (N) and A is cross-sectional area (mm²). Units are typically MPa (N/mm²).

What is the difference between tensile and compressive stress?

Tensile stress occurs when forces pull the material apart (positive σ), while compressive stress occurs when forces push it together (negative σ). The formula σ = F/A is the same, but the direction of force differs. Many materials have different strengths in tension and compression.

What is shear stress?

Shear stress τ = F/A acts parallel to the cross-section surface, tending to slide one part of the material over another. Common in bolts, pins, and rivets. For a bolt in single shear: τ = F/(πd²/4).

What is bending stress?

Bending stress σ = M/W (or M·c/I) occurs in beams and other members subject to bending moments. It varies linearly across the cross-section — maximum at the extreme fibers, zero at the neutral axis. M is bending moment, W is section modulus.

What are typical allowable stresses for steel?

For structural steel (S235): σ_allow ≈ 140–160 MPa (with FoS ~1.5). For S355: σ_allow ≈ 210–240 MPa. High-strength bolts (grade 8.8): τ_allow ≈ 375 MPa. Always check the applicable design standard.

Free Engineering Tool

Stress Calculator

Calculate tensile/compressive stress (σ = F/A), shear stress (τ = F/A), and bending stress (σ = M/W) for common loading scenarios.

σ = F/Aτ = F/Aσ = M/W#166

Results

Calculated Stress

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Stress Type

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Stress in ksi

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Tensile / Compressive Stress

Shear Stress

Bending Stress

ℹ️ 1 MPa = 1 N/mm² = 0.145 ksi. Steel yield strengths typically 235–1000 MPa.

Stress Calculator — Tensile, Shear & Bending | Vibromera

Published by Nikolai Shelkovenko on February 15, 2026 March 5, 2026

Results

Tensile / Compressive Stress

Shear Stress

Bending Stress