Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 218331 found under Drill Straight Flute by Aircraft Service Co Inc. The National Stock Number assigned to this part is 5133013639678, 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 218331.