Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number HL20PB 18 33 found under Heat Exchanger Air by Alcoa Global Fasteners Inc. The National Stock Number assigned to this part is 1660015245385, and the Federal Supply Class is 1660 Aircraft Air Conditioning Heating And Pressurizing Equipment. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like HL20PB 18 33.