Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number W4300-045 found under Washer Spring Tension by Barnes Group Inc. The National Stock Number assigned to this part is 5310010531937, and the Federal Supply Class is 5310 Nuts And Washers. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like W4300-045.