Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 0.5-13UNC-2AX1. 75 STL GRADE 5 found under Screw Cap Hexagon H by Gw Technologies Pty Ltd. The National Stock Number assigned to this part is 5305014149941, and the Federal Supply Class is 5305 Screws. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 0.5-13UNC-2AX1. 75 STL GRADE 5.