Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number AS90991 found under Locknut Tube Fitting by Society Of Automotive Engineers Inc. The National Stock Number assigned to this part is 4730001601645, and the Federal Supply Class is 4730 Hose Pipe Tube Lubrication And Railing Fittings. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like AS90991.