Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 21109-52 found under Stud Plain by Boorum And Pease Co. The National Stock Number assigned to this part is 5307012986190, and the Federal Supply Class is 5307 Studs. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 21109-52.