Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number AT 252DN-12 found under Die Male by Snap On Incorporated. The National Stock Number assigned to this part is 3456004723378, and the Federal Supply Class is 3456 Cutting And Forming Tools For Secondary Metalworking Machinery. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like AT 252DN-12.