Industrial IoT (IIoT) infrastructure for smart manufacturing refers to common facilities based on IoT that support smart manufacturing in industries or sectors. It is independent from the products and production process in specific factories. This article provides requirements and framework of IIoT infrastructure for smart manufacturing to help service providers implementing their system according to the needs of smart manufacturing, and merge existing and newly developed IIoT infrastructures, in order to give the stakeholders of smart manufacturing guidance for their applications.