i guess he's wondering if they finally managed to secure a domestic screw producer or they're if importing them from China?

Houston is a net exporter of screw [0]. But in seriousness, Houston has domestic production of fasteners etc for oil and gas as well as NASA.

0. https://en.wikipedia.org/wiki/DJ_Screw

it's a reference to the last time Apple tried this in Austin, their production was throttled due to the inability of their screw supplier to meet demand.

https://mashable.com/article/apple-mac-pro-screw