Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number HDU-56A found under Stud Shouldered by Valad Electric Heating Corp. The National Stock Number assigned to this part is 5307016015795, and the Federal Supply Class is 5307 Studs. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like HDU-56A.