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This paper presents a feasibility programme undertaken to assess thepotential for using pre-cracked Charpy V-notch (PC-CVN) specimens to measure lowconstraint toughness properties in the cleavage fracture regime. The approach adopted isto use a modified PC-CVN specimen to create a low constraint shallow-cracked three-pointbend specimen. The specimen is prepared by fatigue pre-cracking a short 1mm crack fromthe V-notch, and subsequently removing the upper 2mm of the specimen (including thenotch). The resulting specimen has a width of 8mm, a thickness of 10mm and a cracklength to specimen width ratio of 0.125. Tests have confirmed that this geometry is suitablefor generating low constraint toughness data in the lower transition regime. The dataprovide useful validation for the constraint-based methods in the R6 procedure.