Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 9Y6101 IT 21 found under Key Machine by Caterpillar Inc. The National Stock Number assigned to this part is 5315014210441, and the Federal Supply Class is 5315 Nails Machine Keys And Pins. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 9Y6101 IT 21.