T-Nut Bolts? Wrench does not fit

WTF? It looks like the bolts for the Tnuts are galvanized and put just enough material in the socket that a wrench does not fit. A 3/16 fits in some, and others it does not. Matt at GFC keeps telling me it’s a 5mm allen key, way too big. Wouldn’t a made in USA company use SAE?
So frustrated, now heading to hardware store to buy new 1/4 20 bolts.

I’ve seen some of them be a little tight to begin with due to the galvanization, but nothing a quick hammer tap didn’t fix.


Most 1/4-20 socket head fasteners are 3/16" hex. @dmg5000 is correct some will require a tap in with a hammer to get past the coating, and use a quality hex set since the size varies some on the cheaper ones.

I spoke with someone at GFC, it took the 3rd call to get someone to say it is 3/16 and you need to hit the wrench with a hammer. The consistency between bolts varied greatly. A little better QC would be appreciated, maybe torque specs too.

They do - the threads are 10-32 and 1/4 20, but in my world it’s fairly common that even SAE button head fasteners come with metric heads.

1/4" socket cap screws are most commonly 3/16" (if metric drive, 5mm)
1/4" button cap screws are most commonly 1/8" or 5/32" (if metric drive, 4mm)

Low-height button cap screws can be tricky for hex keys. Any rounding of your hex tool or ball head wrench won’t fit well. Of course it could also just be a bad batch of screws with coatings that are too thick.

Official torque specs are in the Go Fast Campers user manual on page 14, but not every bolt gets a spec.

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