I have the alloy components buried in an old email, but don't have the energy to sift through the archives to find it.
It IS an alloy, NOT straight brass.
Denis
Edited to add:
Across their levergun line-up, Henry uses Zamak 5 for receiver & cover on the rimfire versions. Some models are plated & the GBs obviously get a "golden" coat.
Zamak 5 is the highest grade of Zamak, Henry tweaks their formula slightly, and produces Zamak components in-house via one of the most sophisticated die-casting operations in the country.
Brass centerfires use a different alloy, NOT Zamak.
It is a blend, and formulated & engineered in their applications to exceed industry proof load standards. Those are generally at 30% above standard industry pressures, Henry's alloy & application there has been designed to hold at 40%. (PLEASE DO NOT TRY TO BUILD ATOMIC-LEVEL LOADS FOR THESE GUNS, THIS INFO NEITHER ADVISES NOR CONDONES SUCH PRESSURES!)
ALSO NOTE THAT WE ARE REFERING HERE TO THE FRAMES, NOT THE TOGGLE-LINK ACTION COMPONENTS THEMSELVES IN THE ORIGINALS.
This brass info strictly addresses the alloy strength.
Actual common brass is used in smaller parts like barrel bands on the centerfires.
Centerfire steel-framed leverguns use forged 4140 steel in their frames.