Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 18N AND K4 AND A0404 found under Chuck Drill by Jacobs Mfg Co The. The National Stock Number assigned to this part is 3460002689221, and the Federal Supply Class is 3460 Machine Tool Accessories. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 18N AND K4 AND A0404.