Material property tests involving linear elastic fracture mechanics tests are established within the bearing industry. Plane strain fracture mechanics and threshold stress intensity measures are used as portrayals of the bearing steel functional properties and as a steel quality assurance measure. The perceived attraction in the use of fracture mechanics measures is their use as numerical design limits—for example, ΔK th and K IC measures of defect size limits for fatigue (stable) crack growth and overload fracture, respectively. The sensitivity of impact toughness testing is also evaluated in comparison to plane strain fracture testing. The paper reviews some of the pertinent bearing steel fracture mechanics literature and the relevance of fracture mechanics in steel quality assessment, powder metallurgy (PM), and vacuum induction melting–vacuum arc refining (VIM-VAR) steelmaking through hardening heat treatment and core toughness assessment in carburizing high-temperature rolling bearings. The use of Ashby diagrams of yield strength versus calculated plastic zone size in fracture toughness is demonstrated to evaluate design limits for structurally loaded bearing rings.