# Hall-Petch equation

> English word · Proper noun

## Definitions
1. A relationship between the yield point and grain size of a material given by the equation σ_y = σ₀ + k_y * d^(-0.5), where σ_y is the yield stress, d is the average grain diameter, and σ₀ and k_y are constants specific to a particular material.

## Etymology
Independently discovered by English scientists Eric O. Hall and Norman J. Petch, in 1951 and 1953 respectively.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/hall-petch-equation