Also, if there is a mismatch between the sprue bushing and the nozzle orifice, material may become trapped, hang up, and degrade. For cold sprues nozzle tips should be 1/32 in under-sized to the sprue orifice size, and if running a hot runner the tip and sprue orifice should be 1 to 1 in size. Dead spots between components must be avoided to eliminate any potential material hang up areas.