Troul 

After much digging around & isolating the specs to acquiring the right chain ring guard for the crank set, it now is faced with another dilemma.

The screws that affix the chain ring guard to the crank do not all stay tight. I've ensured the screws are clean, the holes have no grease, & went as far as applying locktite to the threads of the screws.
Unfortunately the screws are not staying torqued & will wiggle loose after riding. It does not happen within a short time of riding, but it will eventually work itself loose.

I am trying to find a better solution than some epoxy with the shallow screws. Are there any shallow headed, small diameter hollow torx screws like what is used for joining crank gears available? If yes, where? Would ideally like stainless or alloy material, but a good corrosion resistant steel could suffice.

shelbyfv

If you are certain the screws are the correct size, just use a different/stronger thread locker. Loctite Threadlocker Red 271 from Loctite Adhesives

Troul 

the screws are self tapping/course thread & the crank holes are non threaded & intended to be threaded by the screws. The screws are too skinny to bite in the slightly larger holes of the crank. As a last ditch effort, I may rivet the guard in place, but that I really do not want to do as someone may have a better hardware suggestion.

CliffordK

You could simply tap the holes to the proper size (slightly oversized)?

Are you using SAE bolts with holes that were sized for Metric?

Troul 

the ring came with screws that were meant for securing it to the crank. There's no tapping the crank as it would not contain enough material to create any threads. I am limited to how much bigger I can go since the ring has a recessed provision for the captive hardware. Cannot have anything protrude too much inboard as that would interfere with the chain engagement. A M3 flat female hex head screw going into a threaded hollow female hex drive post with a shank length of 12 to 14 mm would seem to be what is needed.