When sourcing a used crate mould, you must verify the steel grade (e.g., P20, 718, or S136) as this determines the mould's longevity and wear resistance. Check the cavity number (single or multi-cavity) to ensure it matches your injection molding machine's capacity. Crucially, inspect the cooling system layout to ensure there is no scale buildup, which can significantly impact cycle time and product quality. Request the mould life history to estimate how many shots remain before major refurbishment is required.