Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 2166PC51 found under Ring Hold Down by P M Industries Inc. The National Stock Number assigned to this part is 5365002104005, and the Federal Supply Class is 5365 Bushings Rings Shims And Spacers. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 2166PC51.