Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 4820243 found under Washer Lock by Blackstoneney Ultrasonics Inc. The National Stock Number assigned to this part is 5310014497569, and the Federal Supply Class is 5310 Nuts And Washers. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 4820243.