Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number BN 257-M16 found under Bolt Eye by Bossard Ltd Fasteners. The National Stock Number assigned to this part is 5306121324457, and the Federal Supply Class is 5306 Bolts. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like BN 257-M16.