YHM gas block screw size?

[MrSpiffy]

Does anyone know the screw size for Yankee Hill Machine's low-profile pinch-style gas block? (YHM-9384) The screws they sent with this thing don't seem to match any of the allen wrenches that I have. Either the wrench is just a little too big or too small to drive the screw. And one of the hex sockets is cut off-center, leading me to think these are cheap junk screws. I'd like to get better replacements, but don't know what to buy.

Or maybe I just don't have the proper wrench size..? The instructions don't say what to use.

 

[BBBBill]

Perhaps metric?

 

[MrSpiffy]

It's possible, but I tried both Imperial and Metric wrenches. 5/32" is too small, 3/16" is too large. And 3mm is too small, 4mm too large. I could try a 3.5mm, but I don't have one.

 

[MrSpiffy]

Figured it out... They're 9/64" wrench size... Found another set of wrenches in the garage that had this wrench.