Is there a rational for how the opening sizes are placed on the opposite ends of common wrenches?
I've used open end and box wrenches for over 50 years and this question never occurred to me before this afternoon, when I was laying a set of wrenches out in order on the bench to make sure I hadn't left one behind after fixing daughter's car.
I have a couple of sets of smaller metric sizes of each kind and the opening sizes at the ends of the wrenches in both sets run like this:
6 8
7 9
10 11
12 14
13 15
17 19
I'm wondering why the opening sizes don't ascend sequentially as:
Maybe it's different on the left side of the pond, all my spanners (sorry, wrenches) are arranged in the logical sense you described, e.g 6 +7, 8 +9, etc. I've never seen a set like the first one you described. Martin (on the right of the pond).
Heavy-duty nuts are one size bigger than standard so if you have a standard sized bolt head with a HD nut on it you have two wrenches rather than the two needed sizes on the same wrench.
It is angled so you can get back on the nut when you can only turn it less than 60 degrees. In a confined area when you can't get over a 60 degree turn on the nut, you flip the wrench over and if you moved the nut 30 degrees or more you can get another grip on it.
Erik, I'm going to stay aware from the finer points of the wrench debates.
Still, I can tell you that most open ended wrenches dating back to the turn of the 20th century were straight on, not angled. Having used them, they are quite diffilult to use on modern applications where you have limited circumferencial clearance (maybe I just made up a new word, but I'm sure you know what I mean).
The angled wrenches work much better in these application, but not as well as the so called box wrenches, those totally round things that Sears sells because they don't slip off or generally mar the head of the nut or bolt, but in most cases the racheted socket wrenches work better than anyhing else except where extreme force is called for, in which case I generally use a box wrench.
Wrenches are very interesting to me, because unlike screwdrivers or anything else, they exist in such a variety of forms. Like me, many people own box wrenches specific to loostening the bold underneath an automotive distributor to adjust the engine spark timing. This one is shaped much like the frame on a hacksaw or coping saw, with a box wrench on its end. Another member of my wrench collection is designed to undo and tighten fiting under a kitchen sink...but it would take a plumber to tell us what this rather strange device is called.
After 50 years of home and automotive ownership, I have drawers and drawers filled with special purpose wrenches, many of which have only been used once or twice during those years for very specialized jobs. Risking offending the purists, let me share with you the wrenches that I use year round.... (Right, I can predict content of the followups..)
You should have for home and automotive repairs:
Vice-Grip Pliers, 2, in large and small sizes.
A good pair of Craftman "Pump Pliers" ... These are handy for all sorts of work.
A set of Craftsman (Sears) open-end wrenches (3/8" to 1")
An 18" pipe wrench that can handle 1" pipe fittings (Preferably Rigid Brand).
Needle nosed pliers (Kraeuter).
Diagonal wire cutter and stripper (Kraeuter).
Cheapo wire stripper, crimper, and screw cut-off tool.
Likely I've forgotton somethin. But in one trip to a place like Home Depot or Sears, you should be able to pick us all of the basic grabbers and cutters for less than $150. This is less than the cost of most service calls.
More items are needed for your home and car owners toolbox to be complete, but I'll reserve them for my next post (screwdrivers, hammers, pipe cutters, soldering torches and soldering irons, etc.).
Exactly John. I inherited an large collection of old, head-on, box wrenches, and because of the limited freedom of rotation, they were largely useless.
On Sun, 19 Nov 2006 03:06:52 GMT, with neither quill nor qualm, "Tom Gardner" quickly quoth:
Bingo.
And the angle was determined by trial and error many, many moons ago.
-Very- old wrenches were box ends and then straight open ends. Adding the offset did three things. It made it easier to flip the wrench for use in tight quarters, it reduced slipoffs, and it added strength.
And for Jeff's third (and as yet unasked question), the box end is offset from flat to keep the mechanic's knuckles from scraping.
------------------------------------------- Crapsman tools are their own punishment
The angle is to make the application more flexible. A Wrench (spanner) fits a 6 point nut at 60 degree intervals. A 30 degree offset head allows the wrench to fit in 12 different positions.
As for the staggered sizes,some bolts/nuts have different sizes(AF) on the same thread size. Skipping a size allows one wrench to fit the bolt head, and a different wrench fits the nut. Non staggered sizing would mean you need 2 sets of wrenches to assemble/dissassemble the fastener.
Example, an 8mm bolt could have a 12mm head and a 13mm AF nut. A 10mm bolt can heave a 14mm head, and a 15mm nut.
Sorry Harry, but that is not correct, US makers had been making angled opening wrenches for years before 1900, a style of wrench originating in Britain. "Straight on" opening wrenches of the 20th cen. were basically for agricultural use or basic adjustment use and in a minority of wrenches listed in catalogs by 1900..
Well, that thought occurred to me, thanks for confirming it. Since it only "works" with heavy duty nuts, I figured that if you needed to apply end wrenches on a bolt's head and a standard nut at the same time you'd need two of the same wrenches anyway. But, I agree that for the times a heavy duty nut is involved your answer makes sense.
I can't think of many times I've encountered locations where both a bolt's head and it's nut were situated where only end wrenches could reach them. Usually at least one of the two can be accessed with a socket or box wrench.
Anyone worth his salt probably has sets of all three kinds of wrenches in his kit. Hell, I've got so many wrenches in my house that the place is in danger of breaking through the crust of the earth and sinking into the magma from the sheer weight of those alone.
Another member of my wrench collection is designed
I'm no plumber, but I played one on TV once.
If it looks like this it's called a "basin-wrench":
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And probably never again...I've still got one of those wildly bent distributor bolt wrenches and one of those long flexible shaft distributor point adjusting "screwdrivers" needed for GM cars twenty or more years ago. I don't think many cars even have distributors any more....
I'm suprised you can get much done without at least some metric wrenches nowadays...
That one is easy - The "offset" on it makes it easier to use in places where you can't get a full swing. If the opening were straight, you'd have to be able to get a full 1/6 turn on the bolt/nut to get the wrench back on for the next swing. If you don't have room for a full 1/6 of a turn, that's as far as you get. Game over. Bolt stays there. With it angled the way it is, that tight spot presents less challenge - Flipping the wrench over gives you "fractional adjustment" of the swing, letting you get a bite for the next swing even if you can't get a full 1/6 turn of the bolt for whatever reason.
(But even the offset isn't perfect - It's still possible to find a space so tight that you can't get enough swing to get the wrench back on - But that space is *MUCH* tighter than the swing that would "kill" a straight wrench)
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