Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number K53020-4D10 found under Bolt Close Tolerance by Kenaloy Products Inc Sub. The National Stock Number assigned to this part is 5306003212301, and the Federal Supply Class is 5306 Bolts. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like K53020-4D10.