Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work.

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Default Wrench with non-parallel jaws

The jaws on this wrench are not parallel:

http://home.comcast.net/~bobengelhardt/wrench.jpg

Specifically, the face of the movable jaw is perpendicular to the
"ways", but the fixed face is not. But they aren't sprung or worn that
way. It seems that it was made like that. But why? Just plain poor
quality? But that's *really* bad. It's an old wrench, not Chiwandian.
It says drop forged, if that helps.

Bob

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Default Wrench with non-parallel jaws

The angle of the fixed jaw looks square to the rack slider. The
moveable jaw is definitly a few ° off, and it's not deformed that way
from stress. The quality of machining and finish on the tool
(discounting wear and tear) suggests poor factory work as the culprit.
JR
Dweller in the cellar

On Tue, 10 Jun 2008 21:03:20 -0400, Bob Engelhardt
wrote:

The jaws on this wrench are not parallel:

http://home.comcast.net/~bobengelhardt/wrench.jpg

Specifically, the face of the movable jaw is perpendicular to the
"ways", but the fixed face is not. But they aren't sprung or worn that
way. It seems that it was made like that. But why? Just plain poor
quality? But that's *really* bad. It's an old wrench, not Chiwandian.
It says drop forged, if that helps.

Bob

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Default Wrench with non-parallel jaws

Interesting wrench.

The width of the open jaws is very wide -

I suspect the wrench is a jam on wrench.

Does look odd.

Martin

Martin H. Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
TSRA, Endowed; NRA LOH & Patron Member, Golden Eagle, Patriot's Medal.
NRA Second Amendment Task Force Charter Founder
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http://lufkinced.com/


Bob Engelhardt wrote:
The jaws on this wrench are not parallel:

http://home.comcast.net/~bobengelhardt/wrench.jpg

Specifically, the face of the movable jaw is perpendicular to the
"ways", but the fixed face is not. But they aren't sprung or worn that
way. It seems that it was made like that. But why? Just plain poor
quality? But that's *really* bad. It's an old wrench, not Chiwandian.
It says drop forged, if that helps.

Bob



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Default Wrench with non-parallel jaws

Bob,

My guess is that it is a quality control escapee; either that or it has
been abused at one time or another. I cannot imagine one like that being
purpose-built.

Are you SURE that that is the original jaw??

Flash



"Bob Engelhardt" wrote in message
...
The jaws on this wrench are not parallel:

http://home.comcast.net/~bobengelhardt/wrench.jpg

Specifically, the face of the movable jaw is perpendicular to the "ways",
but the fixed face is not. But they aren't sprung or worn that way. It
seems that it was made like that. But why? Just plain poor quality? But
that's *really* bad. It's an old wrench, not Chiwandian. It says drop
forged, if that helps.

Bob



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Default Wrench with non-parallel jaws


"Bob Engelhardt" wrote in message
...
The jaws on this wrench are not parallel:

http://home.comcast.net/~bobengelhardt/wrench.jpg

Specifically, the face of the movable jaw is perpendicular to the "ways",
but the fixed face is not. But they aren't sprung or worn that way. It
seems that it was made like that. But why? Just plain poor quality? But
that's *really* bad. It's an old wrench, not Chiwandian. It says drop
forged, if that helps.

Bob

I think it was just not a very precise wrench. I have seen this type of
thing in very old tools. I imagine that when it was made its fit was plenty
good enough to turn the big square nuts in use at the time and its strength
might have made it a "quality" tool in spite of its imprecision.

Don Young




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Default Wrench with non-parallel jaws

Bob Engelhardt writes:

The jaws on this wrench are not parallel:

http://home.comcast.net/~bobengelhardt/wrench.jpg

Specifically, the face of the movable jaw is perpendicular to the
"ways", but the fixed face is not. But they aren't sprung or worn that
way. It seems that it was made like that. But why? Just plain poor
quality? But that's *really* bad. It's an old wrench, not
Chiwandian. It says drop forged, if that helps.


It surely looks like one of the lowest quality tools I've seen -- the
imperfections on just about every surface border on bizarre.
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"Joe Pfeiffer" wrote in message
...
Bob Engelhardt writes:

The jaws on this wrench are not parallel:

http://home.comcast.net/~bobengelhardt/wrench.jpg

Specifically, the face of the movable jaw is perpendicular to the
"ways", but the fixed face is not. But they aren't sprung or worn that
way. It seems that it was made like that. But why? Just plain poor
quality? But that's *really* bad. It's an old wrench, not
Chiwandian. It says drop forged, if that helps.




why do you assume that the jaws were NOT sprung by some gross overload?


** Posted from http://www.teranews.com **
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Default Wrench with non-parallel jaws


"Bob Engelhardt" wrote in message
...
The jaws on this wrench are not parallel:

http://home.comcast.net/~bobengelhardt/wrench.jpg

Specifically, the face of the movable jaw is perpendicular to the "ways",
but the fixed face is not. But they aren't sprung or worn that way. It
seems that it was made like that. But why? Just plain poor quality? But
that's *really* bad. It's an old wrench, not Chiwandian. It says drop
forged, if that helps.

Bob


The wrench looks so old that I would think it was made during a time when
metal and craftsmanship were higher than what they are today. But that
being said, they did make cheap crappy wrenches way back when, too. How
long is the wrench? If it's long, there's more of a chance it's been
overtorqued. Or it could have been bad from the get go, but that would not
explain why it got used for that long a period of time.

Puzzling.

Steve


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Default Wrench with non-parallel jaws


"Bob Engelhardt" wrote in message
...
The jaws on this wrench are not parallel:

http://home.comcast.net/~bobengelhardt/wrench.jpg

Specifically, the face of the movable jaw is perpendicular to the "ways",
but the fixed face is not. But they aren't sprung or worn that way. It
seems that it was made like that. But why? Just plain poor quality? But
that's *really* bad. It's an old wrench, not Chiwandian. It says drop
forged, if that helps.

Bob


Another thought ........ that slider is pretty long, indicating that it
could be used for larger heads, hence more chance of tweaking.

Steve


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Default Wrench with non-parallel jaws

On Tue, 10 Jun 2008 21:03:20 -0400, with neither quill nor qualm, Bob
Engelhardt quickly quoth:

The jaws on this wrench are not parallel:

http://home.comcast.net/~bobengelhardt/wrench.jpg

Specifically, the face of the movable jaw is perpendicular to the
"ways", but the fixed face is not. But they aren't sprung or worn that
way. It seems that it was made like that. But why? Just plain poor
quality? But that's *really* bad. It's an old wrench, not Chiwandian.
It says drop forged, if that helps.


Yeah, it's likely that they _are_ sprung, Bob. Look for pipe marks on
the handle length. It was likely 4-6' long.

--
Besides the noble art of getting things done, there is a nobler art of
leaving things undone. The wisdom of life consists in the elimination
of nonessentials. -- Lin Yutang


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Default Wrench with non-parallel jaws



Don Young wrote:

"Bob Engelhardt" wrote in message
...
The jaws on this wrench are not parallel:

http://home.comcast.net/~bobengelhardt/wrench.jpg

Specifically, the face of the movable jaw is perpendicular to the "ways",
but the fixed face is not. But they aren't sprung or worn that way. It
seems that it was made like that. But why? Just plain poor quality? But
that's *really* bad. It's an old wrench, not Chiwandian. It says drop
forged, if that helps.

Bob

I think it was just not a very precise wrench. I have seen this type of
thing in very old tools. I imagine that when it was made its fit was plenty
good enough to turn the big square nuts in use at the time and its strength
might have made it a "quality" tool in spite of its imprecision.

Don Young


Looks just like the wrenches you can buy today brand new from Horrible
Fright... I refer to them as 'self adjusting slip wrenches'

Carla
One day, a man came home and was greeted by his wife dressed in a very
sexy nightie. "Tie me up," she purred, "and you can do anything you
want." So he tied her up and went golfing.
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Default Wrench with non-parallel jaws


"Bob Engelhardt" wrote: (clip) the face of the movable jaw is perpendicular
to the
"ways", but the fixed face is not.(clip)

^^^^^^^^^^^^^^^^^^^
Can you remove the movable jaw and measure the angle between the face and
the "tang?" When you overlead this type of wrench, that's the most likely
place for it to bend. I realize that is in conflict with your statement
that the movable jaw is 90 degrees to the "ways," but it is still worth
checking. I disagree with those who think it may have been made that way on
purpose. That would be like building a car with a flat tire G.


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Default Wrench with non-parallel jaws

My suspicion is that this wrench has been abused in the past
and then had the jaws ground or filed freehand in an attempt
to fix it. Look at the curve at the start of the fixed jaw
and the sharp 90 degree corner of the movable jaw. If it had
been manufactured that way, it would never have closed
completely.

I have a ten inch long or there abouts monkey wrench that I
have used a three or four foot pipe on that looks very
similar except for the fact that yours could never have
closed tight.

Also, this may have been manufactured as part of a line that
is mostly hand made where each movable jaw is fitted to the
individual wrench that it was sold with. If a person had two
of them, it would be easy to assemble them with mismatched
parts.

Ron


Bob Engelhardt wrote:
The jaws on this wrench are not parallel:

http://home.comcast.net/~bobengelhardt/wrench.jpg

Specifically, the face of the movable jaw is perpendicular to the
"ways", but the fixed face is not. But they aren't sprung or worn that
way. It seems that it was made like that. But why? Just plain poor
quality? But that's *really* bad. It's an old wrench, not Chiwandian.
It says drop forged, if that helps.

Bob

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Default Wrench with non-parallel jaws

Thanks for all the comments - some interesting and likely ideas. The
bottom line is that I shouldn't let myself get distracted with stuff
like that. Toss it & forget it.

Thanks again,
Bob
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Default Wrench with non-parallel jaws

On Wed, 11 Jun 2008 20:51:26 -0400, Bob Engelhardt
wrote:

Thanks for all the comments - some interesting and likely ideas. The
bottom line is that I shouldn't let myself get distracted with stuff
like that. Toss it & forget it.


Make sure it isn't worth something before you toss it.
http://www.wrenchingnews.com/ervin-a...8/catalog.html

--
Ned Simmons


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Ned Simmons wrote:
Make sure it isn't worth something before you toss it. ...


Here's one exactly like it, sold for $4:
http://cgi.ebay.com/_W0QQitemZ330241...QQcmdZViewItem
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Default Wrench with non-parallel jaws

I bet Steve has the thought.

If a wrench is used 'backwards' - the weak side might break.
So the jaw was taken from a larger wrench - the long thread bar hangs out...
Maybe the larger wrench had a broken handle from a pipe assist!

Martin

Martin H. Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
TSRA, Endowed; NRA LOH & Patron Member, Golden Eagle, Patriot's Medal.
NRA Second Amendment Task Force Charter Founder
IHMSA and NRA Metallic Silhouette maker & member.
http://lufkinced.com/


SteveB wrote:
"Bob Engelhardt" wrote in message
...
The jaws on this wrench are not parallel:

http://home.comcast.net/~bobengelhardt/wrench.jpg

Specifically, the face of the movable jaw is perpendicular to the "ways",
but the fixed face is not. But they aren't sprung or worn that way. It
seems that it was made like that. But why? Just plain poor quality? But
that's *really* bad. It's an old wrench, not Chiwandian. It says drop
forged, if that helps.

Bob


Another thought ........ that slider is pretty long, indicating that it
could be used for larger heads, hence more chance of tweaking.

Steve




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On Jun 11, 11:04*pm, "Martin H. Eastburn"
wrote:

If a wrench is used 'backwards' - the weak side might break.
So the jaw was taken from a larger wrench - the long thread bar hangs out....
Maybe the larger wrench had a broken handle from a pipe assist!

Martin

- Show quoted text -


I'll bite, Martin. Which way do most people consider is backwards,
and which correct?

John Martin
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On Thu, 12 Jun 2008 07:34:05 -0700 (PDT), John Martin
wrote:

On Jun 11, 11:04*pm, "Martin H. Eastburn"
wrote:

If a wrench is used 'backwards' - the weak side might break.
So the jaw was taken from a larger wrench - the long thread bar hangs out...
Maybe the larger wrench had a broken handle from a pipe assist!

Martin

- Show quoted text -


I'll bite, Martin. Which way do most people consider is backwards,
and which correct?


Now you've done it, John. g (Just keep repeating to yourself, "The
sum of the forces is is zero; the sum of the moments is zero; you
can't push a string.")

--
Ned Simmons
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Default Wrench with non-parallel jaws

On Thu, 12 Jun 2008 11:58:11 -0400, Ned Simmons
wrote:

On Thu, 12 Jun 2008 07:34:05 -0700 (PDT), John Martin
wrote:

On Jun 11, 11:04*pm, "Martin H. Eastburn"
wrote:

If a wrench is used 'backwards' - the weak side might break.
So the jaw was taken from a larger wrench - the long thread bar hangs out...
Maybe the larger wrench had a broken handle from a pipe assist!

Martin

- Show quoted text -


I'll bite, Martin. Which way do most people consider is backwards,
and which correct?


Now you've done it, John. g (Just keep repeating to yourself, "The
sum of the forces is is zero; the sum of the moments is zero; you
can't push a string.")

But you CAN go **** up a rope!
Gerry :-)}
London, Canada


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Default Wrench with non-parallel jaws


"Ned Simmons" wrote in message
On Thu, 12 Jun 2008 07:34:05 -0700 (PDT),

John Martin wrote:
On Jun 11, 11:04 pm,

"Martin H. Eastburn"

wrote:

If a wrench is used 'backwards' - the weak side might

break.
So the jaw was taken from a larger wrench - the long

thread bar hangs out...
Maybe the larger wrench had a broken handle from a pipe

assist!

Martin

- Show quoted text -


I'll bite, Martin. Which way do most people consider is

backwards,
and which correct?


Now you've done it, John. g (Just keep repeating to

yourself, "The
sum of the forces is is zero; the sum of the moments is

zero; you
can't push a string.")

--
Ned Simmons


Oh man oh man, I hope this thread doesn't deteriorate into a
battle on
whether or not 'centrifugal force' exists.......oh oh
.......;)
Phil Kangas, who climbed back up into the peanut gallery....


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Default Wrench with non-parallel jaws

Take a wrench and hang it onto something.

One way you are putting the pressure on the top jaw, the other way
puts it on the bottom jaw.

You normally want it on the top one. The bottom jaw isn't as strong,
being that of a sliding jaw that moves side to side and in and out.
The latter can break if the main force is placed there.

Martin

Martin H. Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
TSRA, Endowed; NRA LOH & Patron Member, Golden Eagle, Patriot's Medal.
NRA Second Amendment Task Force Charter Founder
IHMSA and NRA Metallic Silhouette maker & member.
http://lufkinced.com/


John Martin wrote:
On Jun 11, 11:04 pm, "Martin H. Eastburn"
wrote:
If a wrench is used 'backwards' - the weak side might break.
So the jaw was taken from a larger wrench - the long thread bar hangs out...
Maybe the larger wrench had a broken handle from a pipe assist!

Martin

- Show quoted text -


I'll bite, Martin. Which way do most people consider is backwards,
and which correct?

John Martin



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On Jun 12, 10:23*pm, "Martin H. Eastburn"
wrote:
Take a wrench and hang it onto something.

One way you are putting the pressure on the top jaw, the other way
puts it on the bottom jaw.

You normally want it on the top one. *The bottom jaw isn't as strong,
being that of a sliding jaw that moves side to side and in and out.
The latter can break if the main force is placed there.

Martin


Martin:

I think you're way off the mark with your mention of the "main force".

As I see it, if you're pulling on a wrench with 100 pounds of force on
the end of the handle, then the far jaw should have on it 100 more
pounds of force than the near jaw. It's pretty much meaningless,
though, because it is dwarfed by comparison to the force on the jaws
coming from the nut's trying to wedge them open. That force is equal
on both jaws.

I wasn't trying to set you up with a trick question, though. I do
expect that most people will say as you did: if you are pulling a
wrench, the adjustable jaw should be toward you. I'm not sure that's
right - here's why.

If you're pulling on a wrench with the solid jaw away from you, the
force is at the base of the solid jaw and the tip of the sliding jaw.
The force on the sliding jaw is also to push it against the wrench
frame.

If you're puling on a wrench with the solid jaw toward you, the force
is against the base of the sliding jaw, and is also to pull it away
from the wrench frame.

I'd rather have the force against the base of the sliding jaw, even
though doing it "backwards" like that does try to pull the jaw out of
the frame. But I'd like to hear what some others think.

John Martin
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I suppose you have to do the stress design on the entire part of the wrench.
This wasn't a obtw but from seasoned men I wish I had 1% of in me yelled to
stop...
Martin

Martin H. Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
TSRA, Endowed; NRA LOH & Patron Member, Golden Eagle, Patriot's Medal.
NRA Second Amendment Task Force Charter Founder
IHMSA and NRA Metallic Silhouette maker & member.
http://lufkinced.com/


John Martin wrote:
On Jun 12, 10:23 pm, "Martin H. Eastburn"
wrote:
Take a wrench and hang it onto something.

One way you are putting the pressure on the top jaw, the other way
puts it on the bottom jaw.

You normally want it on the top one. The bottom jaw isn't as strong,
being that of a sliding jaw that moves side to side and in and out.
The latter can break if the main force is placed there.

Martin


Martin:

I think you're way off the mark with your mention of the "main force".

As I see it, if you're pulling on a wrench with 100 pounds of force on
the end of the handle, then the far jaw should have on it 100 more
pounds of force than the near jaw. It's pretty much meaningless,
though, because it is dwarfed by comparison to the force on the jaws
coming from the nut's trying to wedge them open. That force is equal
on both jaws.

I wasn't trying to set you up with a trick question, though. I do
expect that most people will say as you did: if you are pulling a
wrench, the adjustable jaw should be toward you. I'm not sure that's
right - here's why.

If you're pulling on a wrench with the solid jaw away from you, the
force is at the base of the solid jaw and the tip of the sliding jaw.
The force on the sliding jaw is also to push it against the wrench
frame.

If you're puling on a wrench with the solid jaw toward you, the force
is against the base of the sliding jaw, and is also to pull it away
from the wrench frame.

I'd rather have the force against the base of the sliding jaw, even
though doing it "backwards" like that does try to pull the jaw out of
the frame. But I'd like to hear what some others think.

John Martin



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On Thu, 12 Jun 2008 22:20:06 -0400, "Phil Kangas"
wrote:


Oh man oh man, I hope this thread doesn't deteriorate into a
battle on
whether or not 'centrifugal force' exists.......oh oh
......;)


It could be worse, the thermodynamics of air pressure regulators
hasn't come up recently. g

--
Ned Simmons


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On Thu, 12 Jun 2008 22:11:56 -0700 (PDT), John Martin
wrote:

On Jun 12, 10:23*pm, "Martin H. Eastburn"
wrote:
Take a wrench and hang it onto something.

One way you are putting the pressure on the top jaw, the other way
puts it on the bottom jaw.

You normally want it on the top one. *The bottom jaw isn't as strong,
being that of a sliding jaw that moves side to side and in and out.
The latter can break if the main force is placed there.

Martin


Martin:

I think you're way off the mark with your mention of the "main force".

As I see it, if you're pulling on a wrench with 100 pounds of force on
the end of the handle, then the far jaw should have on it 100 more
pounds of force than the near jaw. It's pretty much meaningless,
though, because it is dwarfed by comparison to the force on the jaws
coming from the nut's trying to wedge them open. That force is equal
on both jaws.

I wasn't trying to set you up with a trick question, though. I do
expect that most people will say as you did: if you are pulling a
wrench, the adjustable jaw should be toward you. I'm not sure that's
right - here's why.

If you're pulling on a wrench with the solid jaw away from you, the
force is at the base of the solid jaw and the tip of the sliding jaw.
The force on the sliding jaw is also to push it against the wrench
frame.

If you're puling on a wrench with the solid jaw toward you, the force
is against the base of the sliding jaw, and is also to pull it away
from the wrench frame.

I'd rather have the force against the base of the sliding jaw, even
though doing it "backwards" like that does try to pull the jaw out of
the frame. But I'd like to hear what some others think.


I agree with your conclusion, and I think for the same reasons. But I
don't agree that the "wrong" way applies the force on the moving jaw
in a different direction, i.e., pulls the jaw away from rather than
pushes it toward the frame.

To apply a torque to the nut there are two equal and opposite forces
(a couple, in statics jargon) applied to diagonally opposite corners
of the nut. (As you said, we can safely ignore the relatively small
force applied to the handle by your hand.) So depending on which way
you apply the wrench, the force on the adjustable jaw can be acting
either near the frame or near the tip of the jaw. In either case the
force applied to each jaw face is the same magnitude and direction,
and is resisted by the adjusting screw. What differs is the moment
produced by that force, which is trying to pry the jaw out of the
frame, and that moment increases as the point of application of the
force moves away from the frame.

Mark me down for pull with fixed jaw towards you.

--
Ned Simmons
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On Jun 13, 11:26*pm, Ned Simmons wrote:

I agree with your conclusion, and I think for the same reasons. But I
don't agree that the "wrong" way applies the force on the moving jaw
in a different direction, i.e., pulls the jaw away from rather than
pushes it toward the frame.

To apply a torque to the nut there are two equal and opposite forces
(a couple, in statics jargon) applied to diagonally opposite corners
of the nut. (As you said, we can safely ignore the relatively small
force applied to the handle by your hand.) So depending on which way
you apply the wrench, the force on the adjustable jaw can be acting
either near the frame or near the tip of the jaw. In either case the
force applied to each jaw face is the same magnitude and direction,
and is resisted by the adjusting screw. What differs is the moment
produced by that force, which is trying to pry the jaw out of the
frame, and that moment increases as the point of application of the
force moves away from the frame.

Mark me down for pull with fixed jaw towards you.

--
Ned Simmons- Hide quoted text -

- Show quoted text -


Ned:

I'm glad you agree that pulling with the fixed jaw towards you makes
sense, because I now know that there are at least two of us doing it
the way that almost all others, in my experience, believe is wrong.

Since those forces are acting on diagonally opposite corners of the
nut, can't you look at the forces on each corner as two vectors - one
perpendicular to the face of the nut (and the face of the wrench), and
one at right angles to it? It's that second one that I'm seeing as
pushing the jaw towards or pulling it away from the frame of the
wrench.

It's been a long time since I took physics, though.

Maybe I should ask my younger son Matt, who has just finished his
second year in the physics PhD program at RPI. Here's a bet - if I do
ask him and he asks some of his physics and engineering buddies - my
bet is that there will be proponents in both camps.

John
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"John Martin" wrote: (clip)Since those forces are acting on diagonally
opposite corners of the
nut, can't you look at the forces on each corner as two vectors - one
perpendicular to the face of the nut (and the face of the wrench), and
one at right angles to it? (clip)
^^^^^^^^^^^^^^^^^^^^
Yes, the forces can be resolved into two vectors, as you say, but if the
wrench is properly adjusted, the forces are essentially at right angles to
the jaw faces, so the second vector component is negligible. What makes the
difference is that one of the forces is close to the base of the jaw, and
the other is nearer the tip. Since the forces are equal, the one nearer the
tip creates more bending moment. You want this to be in the stronger jaw.

The movable jaw transmits its moment into the slot in the handle, which is
likely to be weaker than the stationary jaw. So you want it to receive less
moment. Therefore, turn the wrench so the force on the movable jaw is away
from, the tip.


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On Sat, 14 Jun 2008 16:34:36 GMT, "Leo Lichtman"
wrote:



The movable jaw transmits its moment into the slot in the handle, which is
likely to be weaker than the stationary jaw. So you want it to receive less
moment. Therefore, turn the wrench so the force on the movable jaw is away
from, the tip.


Count that five for those that understand moments. I could never understand
how people could convince themselves that the other way was right.


Mark Rand
RTFM
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"Mark Rand" wrote in message
On Sat, 14 Jun 2008 16:34:36 GMT,

"Leo Lichtman" wrote:



The movable jaw transmits its moment into the slot in the

handle, which is
likely to be weaker than the stationary jaw. So you want

it to receive less
moment. Therefore, turn the wrench so the force on the

movable jaw is away
from, the tip.


Count that five for those that understand moments. I could

never understand
how people could convince themselves that the other way

was right.


Mark Rand
RTFM


Perhaps it is more a mental/physical preference in the
handling of the
adjusting screw more than a study of forces for most people.
Seems
to me that when the pressure is applied to the outer tip of
the movable
jaw the leading edge of that jaw is under tension. When the
force
applied is closer to the slideway the force applied is more
in line with
the adjusting screw axis. So how 'strong' are the adjusting
threads
when loaded like this?
Phil Kangas




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"Mark Rand" wrote in message
...
On Sat, 14 Jun 2008 16:34:36 GMT, "Leo Lichtman"

wrote:



The movable jaw transmits its moment into the slot in the handle, which is
likely to be weaker than the stationary jaw. So you want it to receive
less
moment. Therefore, turn the wrench so the force on the movable jaw is
away
from, the tip.


Count that five for those that understand moments. I could never
understand
how people could convince themselves that the other way was right.


Mark Rand
RTFM

Is it possible that the "right way" was really established for the "monkey
wrench" with the jaws at right angles to the handle? It would seem obvious
that you would not want to pull them in a direction that might cause them to
slip off.

I also wonder if anyone has done any actual testing to establish which way
the wrenches are stronger?

Another thought is that if you put a very long "cheater" on the wrench the
pulling force on the wrench handle can be very small. Maybe we need to use
them the "right" way for short handles with lots of pull and then turn them
over to the "wrong" way when we put a "cheater bar" on!

What if you folded the wrench head over so the jaw opening faced the handle?
Which way should you pull it then?

This question really should be resolved so we can get on with other equally
important matters.

Don Young


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"Don Young" wrote:
"Bob Engelhardt" wrote in message
...
The jaws on this wrench are not parallel:

http://home.comcast.net/~bobengelhardt/wrench.jpg

Specifically, the face of the movable jaw is perpendicular to the
"ways", but the fixed face is not. But they aren't sprung or worn that
way. It seems that it was made like that. But why? Just plain poor
quality? But that's *really* bad. It's an old wrench, not Chiwandian.
It says drop forged, if that helps.

Bob

I think it was just not a very precise wrench. I have seen this type of
thing in very old tools. I imagine that when it was made its fit was
plenty good enough to turn the big square nuts in use at the time and its
strength might have made it a "quality" tool in spite of its imprecision.

Don Young


That's an interesting idea. Might a wrench with slightly open jaws like
that actually be easier to use on square nuts? With square nuts, you
certainly don't need as close a fit as you do with hex nuts to prevent
damage and slipping. With the slightly open jaws, you could just push the
wrench into the nut until it wedged on the nut and get a tight fit (at 3
points). A problem with adjustable wrenches is that when you adjust them
to be snug, they tend not to come off, and or are hard to put on, so you
have to either open them just slightly to use them, or tighten and loosen
them for every turn. Might an open jaw design actually make it easier to
get on and off and still allow a fairly tight fit and not risk much damage
if you only used it on square nuts???

So maybe it was intentionally designed that way if the expected use was for
square nuts?

Bob - got any square nuts you can try it on (I just searched my shop and
had a damn hard time finding a square nut - I found some holding one of my
metal shelves together....

--
Curt Welch http://CurtWelch.Com/
http://NewsReader.Com/
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Mark Rand wrote:
On Sat, 14 Jun 2008 16:34:36 GMT, "Leo Lichtman"
wrote:


The movable jaw transmits its moment into the slot in the handle, which
is likely to be weaker than the stationary jaw. So you want it to
receive less moment. Therefore, turn the wrench so the force on the
movable jaw is away from, the tip.


Count that five for those that understand moments. I could never
understand how people could convince themselves that the other way was
right.

Mark Rand
RTFM


It's not so hard to understand. There are a couple of extra dynamics at
work here you are not thinking about.

The handle of adjustable wrenches are angled at about 30 deg (half of the
hex nut 60 deg) to make it possible to flip the wrench over in tight places
and continue to turn a hex bolt with minimal movement of handle (allowing
it to be used in tighter locations than a wrench with a handle which was
parallel to the jaws).

This angle creates an issue however. If you push the handle perpendicular
to the rotation of the nut (the normal way you work any wrench) the wrench
will try to push off and slide off the nut if you turn it one way, and it
will tend to slide onto the nut if you push it the other.

Because the fixed head on standard adjustable wrenches is the one further
way from the handle, you must turn the wrench in the "right" way, in order
for the forces to cause the wrench to by pushed onto the nut, instead of
being pulled off the nut.

As the handle comes towards you when you are pulling, you start to apply a
force which is not perpendicular to the handle. When using the wrench the
wrong way, once the wrench gets to 30 deg away from pointing straight at
you, if you keep pulling towards you, the force will be in perfect line for
pulling the wrench off the nut. When using it the right way, it's sill
applying a lot of torque to the nut at that same point helping to keep the
wrench from slipping off. When using the right way, the forces are working
to your advantage to keep the wrench snug against the nut. When using it
the wrong way, the forces are working against you trying to pull the wrench
off the nut.

Adjustable wrenches are designed with jaws strong enough so they won't
break or bend if they are used by a normal strength human without extending
the length of the handle with a cheater bar. You don't need to worry about
the jaw bending or breaking.

What you need to worry about, is the wrench slipping off the nut and
rounding it off in the process (and making your knuckles bloody). This is
why there's a right way and a wrong way to use the wrench.

But then there's the question of why don't they swap the location of fixed
and adjustable jaw so it will both stay on the nut and reduce the force on
the movable jaw.

I think there's yet another dynamic at work here. When the pressure is
applied further out on the adjustable jaw, more pressure gets applied to
the ways, and less pressure gets applied to the adjusting screw. As a
result, there's more friction on the ways, and less force on the screw
working to make it slip open. So I strongly suspect that the two jaws are
located how they are, instead of switched, because it actually works better
to have the force applied further out on the movable jaw to keep it from
slipping open.

So again, if you use the wrench the wrong way, you create yet another risk.
You increase the risk that the pressure will cause the adjusting screw to
turn, allowing the wrench to open - again increasing the odds that you will
strip the nut, and skin your knuckles as well as potentially marring both
jaws as you try to torque down on a nut with the jaws open too far.

So even though you are right that using it the other way will put less
damaging force on the weaker movable jaw, I think that is not the risk you
need to worry about. Keeping the wrench on the nut, and keeping the jaw
from slipping open, is far more important than worry about damage to the
movable jaw. The movable jaw is designed to take the pressure without
damage.

The only exception to this I would see, is if you were using a cheater pipe
and trying to put far more pressure on the wrench than it was designed for,
it might be wise to turn it the other way to minimize the odds of damaging
the movable jaw because it will no doubt be the first part to bend when you
try testing the wrench to destruction like that. But great care must be
taken at the same time to not let the wrench slip off the nut, and to make
sure the jaws aren't slipping open as you stand on that 10 ft pipe.

--
Curt Welch http://CurtWelch.Com/
http://NewsReader.Com/
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Curt Welch wrote:
That's an interesting idea. Might a wrench with slightly open jaws like
that actually be easier to use on square nuts? With square nuts, you
certainly don't need as close a fit as you do with hex nuts to prevent
damage and slipping. With the slightly open jaws, you could just push the
wrench into the nut until it wedged on the nut and get a tight fit (at 3
points). A problem with adjustable wrenches is that when you adjust them
to be snug, they tend not to come off, and or are hard to put on, so you
have to either open them just slightly to use them, or tighten and loosen
them for every turn. Might an open jaw design actually make it easier to
get on and off and still allow a fairly tight fit and not risk much damage
if you only used it on square nuts???

Damn, you're good! That makes perfect sense. And since only the
diagonally opposite points are actually in contact with the nut, it
wouldn't matter if the jaws are parallel or not.

So maybe it was intentionally designed that way if the expected use was for
square nuts?

If we wanted to be generous, we could say so. G

Bob - got any square nuts you can try it on ...

Ah, damn ... I took it back to the dump (Swap Shop) yesterday!

Thanks,
Bob

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"Curt Welch" wrote: (clip) The handle of adjustable wrenches are angled at
about 30 deg (half of the
hex nut 60 deg) to make it possible to flip the wrench over in tight
places
and continue to turn a hex bolt with minimal movement of handle (allowing
it to be used in tighter locations than a wrench with a handle which was
parallel to the jaws). (clip)

Adjustable wrenches are designed with jaws strong enough so they won't
break or bend if they are used by a normal strength human without
extending
the length of the handle with a cheater bar. You don't need to worry
about
the jaw bending or breaking. (clip)

^^^^^^^^^^^^^^^^^^^^^^^
These two statements, taken together, seem to make the entire discussion
academic. When you maike use of the 30 degree offset in tight quarters, you
are making half the pulls the "wrong" way. Since I believe Curt is right
about the strength of the wrench, I now have decided that there IS NO wrong
way.

The "wrong way" to use an adjustable wrench is with a cheater. ;-)




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"Leo Lichtman" wrote in message
...

"Curt Welch" wrote: (clip) The handle of adjustable wrenches are angled
at about 30 deg (half of the
hex nut 60 deg) to make it possible to flip the wrench over in tight
places
and continue to turn a hex bolt with minimal movement of handle (allowing
it to be used in tighter locations than a wrench with a handle which was
parallel to the jaws). (clip)

Adjustable wrenches are designed with jaws strong enough so they won't
break or bend if they are used by a normal strength human without
extending
the length of the handle with a cheater bar. You don't need to worry
about
the jaw bending or breaking. (clip)

^^^^^^^^^^^^^^^^^^^^^^^
These two statements, taken together, seem to make the entire discussion
academic. When you maike use of the 30 degree offset in tight quarters,
you are making half the pulls the "wrong" way. Since I believe Curt is
right about the strength of the wrench, I now have decided that there IS
NO wrong way.

The "wrong way" to use an adjustable wrench is with a cheater. ;-)


I'm relieved to know that (with common angled adjustables, anyway) there is
no **WRONG** way. Dad, who became a mechanic when monkey wrenches were in
fashion, always taught me to pull against the standing jaw. His other
advice, equally sage, was always to pull on the wrench - never push.
Disregarding his warnings, I have gathered a scar or two.

Flash


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