The title says it: hex or square? 7/6"or 1/2" wrench size? This is on the 1923 touring.
The general rule of thumb is carriage bolts get square nuts.
The rule applies.
Is this for your '15? Larry Smith shows original bolt with nut for '13 '14 here:
Also front and rear lenghts are discussed.
Rich, read again.
Steve, another rule of thumb which can roughly be applied, [like the thumb I mangled with a hatchet when I was a kid] is; If a square nut is called for on a T, it is usually the larger size available.
Just from my observations over the years.
Allan from down under.
OK. I'm Sorry. This is from a supposedly untouched Tudor. '24 or '25. It measures 1/2 across flats.
I looked at a shelf from the 18 that had been removed, the hardware put back on in one hole with the block, the wire clip and a little piece of busted tin.
The same 1/2" across the flats nut as Rich shows. :-)
I wondered about that little piece of tin for a year. I bet it's part of the engine splash pan. :-)
Learning thread for me! Thank you! The replacement hardware from 30 years ago isn't quite up to snuff...
Thanks Duey. The piece of engine splash pan shown makes me believe this nut hasn't been unscrewed since it was assembled in the factory.
The 24-25 bolt in the picture doesn't have the cotter pin hole mentioned in the link. I wonder when that went away.
Steve: This is a good point. I try to know this stuff, but you got me on this one. For a '15 the nut is probably still 7/16 across, but that is only a guess. They probably stopped putting the cotter pin hole in them because of the labor involved to assemble them. Most likely, the slotted head on the carriage bolt was gone by then too.
I would assume the '23s are using a 1/2" across the flats square nut. The '25s definitely do. Randall Anderson is selling them now because they are so hard to find. I've been collecting them for years, because I've been aware of the scarcity of them.