Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 4H8158 found under Ring Retaining by Caterpillar Inc. The National Stock Number assigned to this part is 5325008487439, and the Federal Supply Class is 5325 Fastening Devices. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 4H8158.