In part I of this series, experimental investigation in EPFM (elastic-plastic fracture mechanics) had been discussed. In this paper, experimental investigation in LEFM (linear elastic fracture mechanics) is given. Fracture toughness tests had been carried out on three different strength steels, using both through-cracked specimens with different a/W ratio and semi-elliptical cracked specimens with variable crack size and shape. Results show that the fracture toughness K_ IC increases with decreasing a/W when a/W<0.3 for three-point-bend specimens, and that for a/W>0.3, it is independent of a/W. Shallow crack specimens, both through-cracked and surface-cracked, gave markedly higher values than deeply notched specimens. However, the effect of crack shape on fracture toughness is negligible. Results also show that the LEFM approach to fracture is not tenable for design stresses where a_c is often very small, far less than 2.5(K_ IC /σ_y)~2. In part I of this series, experimental investigation in EPFM (elastic-plastic fracture mechanics) had been discussed. In this paper, experimental investigation in LEFM (linear elastic fracture mechanics) is given. Fracture toughness tests had been carried out on three different strength steels, using both through-cracked specimens with different a / W ratio and semi-elliptical cracked specimens with variable crack size and shape. Results show that the fracture toughness K_ IC increases with decreasing a / W when a / W <0.3 for three- point-bend specimens, and that for a / W> 0.3, it is independent of a / W. Shallow crack specimens, both through-cracked and surface-cracked, gave markedly higher values ​​than deeply notched specimens. However, the effect of crack shape on fracture toughness is negligible. Results also show that the LEFM approach to fracture is not tenable for design stresses where a_c is often very small, far less than 2.5 (K_IC / σ_y) ~ 2.