Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 6D6538 found under Stud Plain by Caterpillar Inc. The National Stock Number assigned to this part is 5307010667674, 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 6D6538.