I was going through an aluminum door opening the other day (OK, I confess, I checked out all the hardware on the opening) The door opening had concealed vertical rod panics, and half moon shape offset pull handles and the only thing different was the use of hex head screws for the pull handle on the inside. This told me that the mounting was the heavy duty type 5/16 - 18 machine screw.  And because it had a regular finish washer - it told me it was a type 1HD Mounting.

All pull handles can be special ordered with the heavy duty mounting.

Rockwood Pull Handles Mounting Types

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