[Spktyr]

Nobody else did either. The Germans use odd-number-sized fasteners. Everyone else uses the Japanese standard of even-number through 14mm, then odd numbered in general from 15mm and up.

[Paladin2]

The American auto industry went Metric but kept fasteners close to the English stuff.

Hence all the need for 16mm and 18mm tools. The Brake manufacturers all went with 7 mm hex allen tools to pull caliper slide bolts and the Japs went with 5mm hex allens to do Stabar links. Only a few bucks to get there, but somehow Harbor Freight is not up to speed. Weird.

[Organic Panic]

Nobody else did either. The Germans use odd-number-sized fasteners. Everyone else uses the Japanese standard of even-number through 14mm, then odd numbered in general from 15mm and up.

The first socket set I ever bought, straight out of high school, was at the Kmart in South Lake Tahoe (at the Y for anyone who knows). It was the Benchtop brand Metrinch tools. It predates the spline drive they are selling all over the place now. In my opinion the "universal" spline drive is garbage. Metrinch is awesome. I still have my 3/8 and 1/4 set. I have rebuilt my old beaters with these sets before I had a professional tool set. They are still on my top shelf of the tool chest. When I take a road trip, they are in my saddle bag or car tool set.