Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number UDB915013-8438 found under Drill Twist by United Drill Bushing Corporation. The National Stock Number assigned to this part is 5133010704939, and the Federal Supply Class is 5133 Drill Bits Counterbores And Countersinks Hand And Machine. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like UDB915013-8438.