On Tue, 3 Dec 2019 14:39:35 -0500, Ralph Mowery
wrote:

In article ,
says...

Not always in larger sets. But like who would buy an SAE set of any size if
it ran from say 3/8 to 3/4 without a 9/16?

Also a metric socket set covering the same range as a 13 piece SAE set starting at 7/16 would requier 10 more sockets to be compleat.



I fail to understand why there are wrenches that are sized so close to
each other, not counting the need to fit bolts that should not be made
either.

The SAE of going up 1/16 of an inch or less in sizes over 3/4 of an inch
seems just as bad.

Does a bolt really have much more strength in size 21 than a size 20 in
metric ? I would think that as wrenches/bolts reach around size 12
metric they would go up in steps of 3 to 4 to gain enough to make them
worth while to make.
7mm, 9mm 11mm and 13mm thread sizes are almost non-existant "in the
wild" and in larger sizes the gaps ARE much larger, in the real world.
The difference in head sizes per bolt size between "systems" makes the
full size range important - not the 1mm incement in thread sizes.