Harvey,
EM here does not stock bronze machine screws. On the way home, stopped by and looked at catalog info on a couple Groco bronze valves equipped with bonding connection points. No specifics on size, thread pitch of screw. EM suggests you contact their sales desk with P/N of valve you have, and call GROCO for screw specs needed, or order same
GROCO (closes 500 pm EDT) : 410-604-3800
Good luck.