Double square bit screw???

[mikeyk101]

So I learned about the Roberson head screws just 2 years ago after getting my first regular camper. Pretty much everything is tightened down or attached with Roberson square bit screws. Now I am starting a new chapter with an enclosed cargo trailer.

I just had my first oops. I was backing the cargo trailer up solo (my mistake) to get it parked behind the house. It's a pretty tight area and the random trees back there I have to avoid dont help either. I haven't decided yet in a rear view camera but that's will be soon. As I was slowly and (I thought) carefully, I ended up clipping the left rear corner and snapping off the license plate light. Luckily I stopped quick and don't think there was any other damage. So I ordered a replacement and was going to install it today. I thought the screws were torx bits. I first tried a T20, too big. Then a T15, too small. So I broke out both my sets of Allen wrenches, SAE and metric. Nope, those won't work either. A quick Google search and I found that quite a few were able to use Roberson #2 square bits to loosen these screws. I found my Roberson bits and sure enough, the #2 seemed to fit nicely. But it still didn't grab well enough and spun without the screw loosening. A little more searching and I discovered that these are 8 point screws also known as double square bit screws. So I learned something new today.

I found (I think) the proper 8 point double square bits on Amazon and they are supposed to be coming overnight. I had never heard of these things before but looks like I will now be adding to my tool collection. It never seems to end. I am hopeful that with these bits, I will be able to remove the mounting screws to replace that light. Otherwise I will have to get medieval on it and drill out the old ones. Wouldn't be the first time doing that. Either way, it appears that there are many of these screws used all over this trailer so I needed these new bits anyway.

[swoody126]

T20

sw

[mikeyk101]

T20

sw

Nope, tried that and too big. The Roberson #2 square bit was a much closer fit but not enough. I ordered a set of the 8 point double square bits on Amazon last night and they came overnight. The bits fit even better but still didn't grab. A couple taps in back of bit with a hammer fully seated it. Old screws now out, new license plate light installed and working.

And what's with using scotchlock connectors for wiring? That's about the cheapest wiring solution possible. I used Wago lever lock connectors to attach the new light and eventually plan on replacing all those stupid scotchlock connectors with the Wagos.

[Squigie]

Sounds like a spline socket screw.
They're showing up more frequently these days, especially with self-tapping screws.

Very irritating when working on cars, trailers, ATVs - pretty much anything.
You need SAE and metric wrenches. Then SAE and metric hex wrenches. Then Torx bits. Then E-bits, but not normal sizes, you need half steps, like a tiny little 4.5mm E-bit.
But, wait! Here are three spline socket screws, just for fun, and none of your other bits will fit them.
But first, you must remove a bracket. On one side of the bracket, there's a half-inch bolt. On the other, there's a 10mm Pentabolt!
"What? You don't have penta sockets? How dare you buy our products and consider doing your own maintenance without owning a $900 socket set that you'll use twice!"
"How about one more little treat for you: There are penta spline bolts hiding behind the heat shield that you can't see around yet."

It may be coincidence, but most of these [redacted] evil fasteners didn't really seem to start showing up in vehicles until states started passing Right-To-Repair laws.
"You may have the right to repair it, but we can make that very difficult."

[mikeyk101]

You may be on to something there. And yes, the tool collection keeps growing larger Everytime I turn around...