Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 18 BL SL found under Tape Lacing And Tying by Gudebrod Inc. The National Stock Number assigned to this part is 4020007536555, and the Federal Supply Class is 4020 Fiber Rope Cordage And Twine. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 18 BL SL.