Compression testing of cast iron: fracture orientation In a compression test on a cast iron specimen (a brittle material), indicate the most likely fracture path. Select the correct description.

Concept
Brittle materials like cast iron fail in compression by shear along planes where maximum shear stress acts, typically around 45° to the axis of loading.

Why not others?
Fracture perpendicular to the axis is more typical in tension; axial cracking is not the governing failure mode in brittle compression; brittle specimens can and do fracture in compression.

Final Answer
Along an oblique plane (≈ 45° to axis).