Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 251LG NO. 20 found under Needle Sewing Machine by B And G Lieberman Co Inc. The National Stock Number assigned to this part is 3530015640994, and the Federal Supply Class is . Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 251LG NO. 20.