The die-casting family on hs-inst.com is short and specific: a 5G / base-station equipment shell, a transmission case, a set of high-precision automotive aluminum parts, and a generic aluminum-alloy shell.
All four listings use the same process sentence — “die-casting manufacturing” — and three of them name aluminum alloy. The alloy grade, heat-treat, and machining after cast are not published. Treat those as TBC on the RFQ.
The finned shell photograph includes a caliper on the bench. That is the strongest evidence the shop inspects cast housings in-house rather than only showing a stock rendering.