When sourcing a used chair mould, you must prioritize the mould steel type (e.g., P20, 718, or S136) as it determines the remaining life and surface finish quality. Verify the cavity and core condition for any signs of rust, cracks, or excessive wear. Additionally, confirm the mould dimensions and weight to ensure compatibility with your existing injection molding machine's clamping force and tie-bar spacing. It is essential to request the original cycle time data to estimate production efficiency.