Wrenches with 11/16" and 7/8" on each end?

Picked up two wrenches at a yard sale. Why would 11/16" and 7/8" be paired up on the same wrench? Why would you skip 3/4" and 13/16"? Are they special purpose?

Maybe I should wait until after my 2nd cup of coffee before asking. Is this a dumb question?

[troyadamietz]

perhaps for use on a specific machine?

[RichR]

Maybe it's related to mating nuts and bolts sometimes requiring different size wrenches? So when you grab a wrench for the bolt, the size you
need for the nut isn't at the other end of the same wrench?

[BCRider]

It has to be for something special. I'm thinking that these sizes would be the fittings in plumbing for example? Not sure about plumbing fitting sizes at the moment though. I'd have to check some fittings.

I've got some old wrenches I originally bought in the mid 1970's that have different sizes on each end. But they are 1/16" increments, not 3/16". So 11/16 to 7/8 does not seem normal.

[J Tiers]

It would make sense to me to have sizes that DO NOT go together on opposite ends of one wrench.

Think about it.... If you have sizes on one wrench that you would use at the same time, then you need two sets of wrenches. But if they are on different wrenches, then one set may do it for you.

Now, with modern screws and nuts that have a common size for both head and nut, it does not do much good. But with nuts of a different size to the bolt head, which has been common in the past, then you would be in good shape so long as the head and nut sizes are on different wrenches.

[Willy]

I think JT has it right as it only makes sense.
I have an old set set of Dowidat (old German wrench set) deep offset box ends that have some unusual size combinations like the one the OP mentioned. The one I was using this morning has 3/4" on one end and 25/32" on the other and it has come in handy occasionally.

[cameron]

It would make sense to me to have sizes that DO NOT go together on opposite ends of one wrench.

Think about it.... If you have sizes on one wrench that you would use at the same time, then you need two sets of wrenches. But if they are on different wrenches, then one set may do it for you.

Now, with modern screws and nuts that have a common size for both head and nut, it does not do much good. But with nuts of a different size to the bolt head, which has been common in the past, then you would be in good shape so long as the head and nut sizes are on different wrenches.

I think it only makes sense if you want to restrict yourself to the minimum number of wrenches you want to buy, or carry in your tool box. You do need two open end wrenches of each common size if you work on tube or hose fittings, and don't want to use an adjustable wrench. The usual open end wrench set gives you that, with the large end of one wrench being the same as the small end of the next larger wrench.

But the optimum choice, balancing usefulness with minimum weight would be to have a complete set of combination wrenches and a half-set of open ends. That is, leave out every second open end wrench in a set.

But then, who in his or her right mind would ever go anywhere without socket wrenches?

[Jim Stewart]

I bought my first set of Craftsman end wrenches in the late '60s - geez, nearly 50 years ago. Still have all of the set. It had 13/16 and 3/4 paired up, and 11/16 with 7/8 - so there's nothing new about that combination. Seems to me that in Ye Olden Dayes you often found nuts larger than their matching bolt head, so that's likely the reason.

-js

[J Tiers]

I think it only makes sense if you want to restrict yourself to the minimum number of wrenches you want to buy, or carry in your tool box. You do need two open end wrenches of each common size if you work on tube or hose fittings, and don't want to use an adjustable wrench. The usual open end wrench set gives you that, with the large end of one wrench being the same as the small end of the next larger wrench.

But the optimum choice, balancing usefulness with minimum weight would be to have a complete set of combination wrenches and a half-set of open ends. That is, leave out every second open end wrench in a set.

But then, who in his or her right mind would ever go anywhere without socket wrenches?

Remember, the whole deal is generally with OLD tools. Mostly these days, the head and the nut are the same size, so you get no advantage.

That set of wrenches back 80 or 90 years might have cost a good bit more as a percentage of pay, and tools are heavy. So having fewer and still being able to do the work made plenty of sense.

[elf]

That must be a pretty weird looking wrench with two different sizes on each end...

[PStechPaul]

That must be a pretty weird looking wrench with two different sizes on each end...

Like this:



Or:

http://www.trucktrend.com/features/1...bone-wrenches/


L

[Steve Steven]

I think JT has it right as it only makes sense.
I have an old set set of Dowidat (old German wrench set) deep offset box ends that have some unusual size combinations like the one the OP mentioned. The one I was using this morning has 3/4" on one end and 25/32" on the other and it has come in handy occasionally.

I have an old (WWII I think) open end wrench with 3/4 and 25/32 openings. Interestingly, the 25/32 end fits the holddown on my 1937 made Van Norman #12 mill.

Steve

[Doozer]

32nd sizes were usually the heavy-hex size version of a nut or bolt.

-Doozer

[Willy]

I have an old (WWII I think) open end wrench with 3/4 and 25/32 openings. Interestingly, the 25/32 end fits the holddown on my 1937 made Van Norman #12 mill.

Steve

The 32nd sizes were very prevalent prior to WWII, they were dropped during WWII in order to streamline maintenance logistics during the war. Since then 1/16" size increments have become the standard.
Yes the old Van Norman mill that a friend has uses them as well, also a pre-WWII unit. I've also found them handy on older cars and trucks built when the 32nd sizes were still popular.

[John Garner]

pgmrdan --

"U S Heavy" hex nuts have nominal across-flats dimensions of 1 1/2 x thread diameter + 1/8 inch; a U S Heavy nut fitting a 3/8 inch diameter screw would take an 11/16 inch wrench, and one fitting a 1/2 inch diameter screw would take a 7/8 inch wrench. Can't say for sure that is why your wrenches were made that way, but maybe.

John