The knob attaches to the housing and is made out of plastic and metal. This part is an OEM from Hitachi for use in planers. This part is available individually. No tools should be needed when replacing this part. It will require replacing if it breaks.
This is an authentic OEM part. The Hitachi knob bolt (m6x11) is composed of threaded metal with a plastic handle. This component is designed for use with many compound miter saw devices. The knob bolt is fitted into the vise (b) assembly, and allows the operator to adjust the height of the vice. This part is sold individually. No tools should be necessary for the replacement.