Official Answer
Answer
Fracture during installation is almost always due to 'Over-Straining' or 'Material Brittleness.' If the material is high-carbon steel, check for Hydrogen Embrittlement if it was recently plated. If it is 17-7PH, check the heat treatment records; 'Over-aging' or 'Under-aging' can result in improper ductility. Geometrically, if the installation mandrel was too large, the fiber stress at the ring's outer diameter would exceed the Ultimate Tensile Strength (UTS). The calculation $\sigma = _x000c_rac{E imes t imes (D_{exp} - D_i)}{(D_i imes D_{exp})}$ should be used to verify that the strain $\epsilon$ during expansion does not exceed the material's 'Elongation at Break' value (typically 5-10% for these alloys).
