After my boss broke my last thumb wrench, I had to make a new one, but I'd lost the old file. This is the 2.0 version. It has more fillets for the fingers to grip better and a stronger square drive. It has a very snug fit for a 1/4" drive socket.
I also uploaded an STL version this time. Let me know if you need a different file format and I'll upload it.
I also used a different filament from Gizmodorks on Amazon. For ABS, its very strong. Even at 20% infill, it feels like its a solid piece! Much stronger than even the nylon one I'd managed to make.