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Stress Concentration Factor (Kt) Calculator

Theoretical Kt for fillets, holes, and notches in plates and shafts.

Estimate the theoretical stress concentration factor and resulting peak stress at common geometric discontinuities.

Reference: Peterson's Stress Concentration Factors (approximation)

Stress Concentration Factor (Kt) Calculator

Inputs

Results

Stress Concentration Factor (Kt)
2.06
Maximum Local Stress
206.3MPa
Approximation valid for hole diameter/plate width ratio between 0 and 1 (Peterson's charts).

Formula Used

σmax = Kt × σnominal
These are curve-fit approximations for quick estimation. For critical/safety applications, use exact values from Peterson's Stress Concentration Factors charts or FEA analysis.

⚠ For preliminary design and educational use only. Verify all results against applicable codes and standards before use in production or safety-critical applications.

About this calculator

Part of our Mechanical Calculators collection. Beams, bolts, springs, gears, bearings, and core ME calculations.

How it works

Estimates theoretical stress concentration factors (Kt) for common stress raisers — shoulder fillets, circular holes, and semicircular notches in plates and shafts.

Enter your values in the inputs above and click CALCULATE. Results appear on the right without a page reload. No login and no server upload.

Privacy and accuracy

Every calculation runs locally in your browser. Your design data never leaves your device. Results are intended for preliminary engineering work. Always verify critical designs with qualified review and applicable standards before production use.

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