The Nov-Dec issue of HSM has the last in a series of 5 articles about
making a tool that _cuts_ knurls. It's an interesting tool and way
beyond my capabilities, but he makes a wrench for the knurling tool that
uses a neat technique.

The wrench is a 1/8" 6 point closed end. He takes a piece of mild steel
round stock, drills a hole that's an interference fit for a 1/8" Allen
key, presses a piece of the key in, and forges the stock to fit the key.
He counts on the hardness of the key resisting the forging. I.e.,
the stock deforms, but not the key. He now has a 1/8" hex hole in the
stock and he slices off a piece to use for the wrench. Long story
short, but you get the point, I hope.

My question is: is mild steel OK to use for a wrench? I thought
commercial wrenches were some kind of hard alloy. And I ask because I'd
like to use this technique to make some square sockets for those square
headed set screws and square nuts. (Why does anybody use square nuts?)

Thanks,
Bob

On 12/07/2010 01:56 PM, Bob Engelhardt wrote:
The Nov-Dec issue of HSM has the last in a series of 5 articles about
making a tool that _cuts_ knurls. It's an interesting tool and way
beyond my capabilities, but he makes a wrench for the knurling tool that
uses a neat technique.

The wrench is a 1/8" 6 point closed end. He takes a piece of mild steel
round stock, drills a hole that's an interference fit for a 1/8" Allen
key, presses a piece of the key in, and forges the stock to fit the key.
He counts on the hardness of the key resisting the forging. I.e., the
stock deforms, but not the key. He now has a 1/8" hex hole in the stock
and he slices off a piece to use for the wrench. Long story short, but
you get the point, I hope.

My question is: is mild steel OK to use for a wrench? I thought
commercial wrenches were some kind of hard alloy. And I ask because I'd
like to use this technique to make some square sockets for those square
headed set screws and square nuts. (Why does anybody use square nuts?)

I've used wrenches made of soft plastic. What are you going to wrench _on_?

You could always make the wrench out of tool steel, then harden it.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" was written for you.
See details at http://www.wescottdesign.com/actfes/actfes.html

In article ,
says...

I'd like to use this technique to make some square sockets for those
square headed set screws and square nuts. (Why does anybody use square
nuts?)

Yeah, we come across them all the time on older garage doors we work on.
But a set of Sears 8 point sockets is all I use.

--
DT

On Dec 7, 2:56*pm, Bob Engelhardt wrote:
The Nov-Dec issue of HSM has the last in a series of 5 articles about
making a tool that _cuts_ knurls. *It's an interesting tool and way
beyond my capabilities, but he makes a wrench for the knurling tool that
uses a neat technique.

The wrench is a 1/8" 6 point closed end. *He takes a piece of mild steel
round stock, drills a hole that's an interference fit for a 1/8" Allen
key, presses a piece of the key in, and forges the stock to fit the key.
* *He counts on the hardness of the key resisting the forging. *I.e..,
the stock deforms, but not the key. *He now has a 1/8" hex hole in the
stock and he slices off a piece to use for the wrench. *Long story
short, but you get the point, I hope.

My question is: is mild steel OK to use for a wrench? *I thought
commercial wrenches were some kind of hard alloy. *And I ask because I'd
like to use this technique to make some square sockets for those square
headed set screws and square nuts. *(Why does anybody use square nuts?)

Thanks,
Bob

Square nuts are cheap to make, punch/drill the hole, tap, shear off
bar. Any blacksmith could do one in a few minutes. Hex nuts either
require drawn/rolled stock or a mill to mill the flats, plus a lathe
or screw machine to drill and tap. Square heads are also a lot harder
round off, even with really sloppy wrenches. You can also capture a
square nut in a slot a lot better than a hex nut.

Prior to crucible and alloy steels, all they had was wrought iron and
casehardening. Worked well enough in the early steam era. Just
depends on how much torque you need to apply. If the handle starts
bending it might be a Clue.

Stan

Vanadium is the alloying element that I see in the tool steel analysis
that's somewhat unique to a wrench. I would NOT make ANY wrench out of
mild steel unless I knew that the torque was going to be very low. Just
try making a simple screwdriver from mild steel and you will see what I
mean.
I have used steels as simple as 1045, hardened and then tempered to
the red temper color, where a medium amount of torque is required.
5160 (leaf or coil spring from most cars made since about 1950) is a
good bet and there's a lot of it around, so you can try different
approaches.
The amount of room you have around the fastener also plays a big part.
If you can make the tool real hefty, it has a better chance of
surviving, obviously.

Pete Stanaitis
------------------

Bob Engelhardt wrote:
The Nov-Dec issue of HSM has the last in a series of 5 articles about
making a tool that _cuts_ knurls. It's an interesting tool and way
beyond my capabilities, but he makes a wrench for the knurling tool that
uses a neat technique.

The wrench is a 1/8" 6 point closed end. He takes a piece of mild steel
round stock, drills a hole that's an interference fit for a 1/8" Allen
key, presses a piece of the key in, and forges the stock to fit the key.
He counts on the hardness of the key resisting the forging. I.e., the
stock deforms, but not the key. He now has a 1/8" hex hole in the stock
and he slices off a piece to use for the wrench. Long story short, but
you get the point, I hope.

My question is: is mild steel OK to use for a wrench? I thought
commercial wrenches were some kind of hard alloy. And I ask because I'd
like to use this technique to make some square sockets for those square
headed set screws and square nuts. (Why does anybody use square nuts?)

Thanks,
Bob

On Dec 7, 3:56*pm, Bob Engelhardt wrote:
The Nov-Dec issue of HSM has the last in a series of 5 articles about
making a tool that _cuts_ knurls. *It's an interesting tool and way
beyond my capabilities, but he makes a wrench for the knurling tool that
uses a neat technique.

The wrench is a 1/8" 6 point closed end. *He takes a piece of mild steel
round stock, drills a hole that's an interference fit for a 1/8" Allen
key, presses a piece of the key in, and forges the stock to fit the key.
* *He counts on the hardness of the key resisting the forging. *I.e..,
the stock deforms, but not the key. *He now has a 1/8" hex hole in the
stock and he slices off a piece to use for the wrench. *Long story
short, but you get the point, I hope.

My question is: is mild steel OK to use for a wrench? *I thought
commercial wrenches were some kind of hard alloy. *And I ask because I'd
like to use this technique to make some square sockets for those square
headed set screws and square nuts. *(Why does anybody use square nuts?)

Thanks,
Bob

Matweb shows AISI 4140 as an alloy commonly used for making wrenches
and hand tools:
Carbon, C = 0.40 %
Chromium, Cr = 1.0 %
Iron, Fe = 97.15 %
Manganese, Mn = .0 %
Molybdenum, Mo 0.20 %
Silicon, Si 0.25 %

On Tue, 07 Dec 2010 16:56:02 -0500, Bob Engelhardt
wrote:

My question is: is mild steel OK to use for a wrench?

Often it is, particularly for special wrenches that don't get a lot of
use and aren't stressed hard when they do get used. I've made a
number of wrenches out of mild steel.


I thought commercial wrenches were some kind of hard alloy.

They are.

On Dec 7, 4:56*pm, Bob Engelhardt wrote:
...He takes a piece of mild steel
round stock, drills a hole that's an interference fit for a 1/8" Allen
key, presses a piece of the key in, and forges the stock to fit the key.
...
Bob

If you can forge steel, maybe you could flatten and round the head of
a Grade 5 bolt and make the round-square punch for the hole out of
key stock. To clean up and size the hole clamp the wrench in a vise
and use the jaws as a filing guide.

I use old Armstrong square wrenches on the lathe, keeping everything
close to original, otherwise 8 point sockets. You can use them to
connect and compare two torque wrenches.

jsw

Tim Wescott wrote:
I've used wrenches made of soft plastic. What are you going to wrench
_on_?

You're right, of course. I suppose the worst case would be removing
square head set screws. As for square nuts, I see them used mostly with
screws, so the torque wouldn't be as much. I don't foresee myself
putting square nuts on anything.

You could always make the wrench out of tool steel, then harden it.

Yeah, I have some O1 & most of the work is in the forging, the heat
treating would be easy enough.

Thanks,
Bob

On Dec 8, 10:13*am, Bob Engelhardt wrote:
Tim Wescott wrote:
I've used wrenches made of soft plastic. *What are you going to wrench
_on_?

You're right, of course. *I suppose the worst case would be removing
square head set screws. *As for square nuts, I see them used mostly with
screws, so the torque wouldn't be as much. *I don't foresee myself
putting square nuts on anything.

You could always make the wrench out of tool steel, then harden it.

Yeah, I have some O1 & most of the work is in the forging, the heat
treating would be easy enough.

Thanks,
Bob

On the old equipment I've bought if an open-end wrench wouldn't loosen
them it was time for Vise-Grips, then replace them with hex or Allen
heads. You can keep the originals for when you finally sell the
machine to an antique collector.

jsw

DT wrote:
...
But a set of Sears 8 point sockets is all I use.

8 point is good. Sears doesn't have the sets, but eBay does. $8 for 5
pcs, 1/4 thru 1/2.

Thanks,
Bob

wrote:
Square nuts are cheap to make, punch/drill the hole, tap, shear off
bar. Any blacksmith could do one in a few minutes. Hex nuts either
require drawn/rolled stock or a mill to mill the flats, plus a lathe
or screw machine to drill and tap.

In the old days. Now I don't think there'd be any difference.

Square heads are also a lot harder
round off, even with really sloppy wrenches. You can also capture a
square nut in a slot a lot better than a hex nut.
....

Good points, both.

Bob

spaco wrote:
....
5160 (leaf or coil spring from most cars made since about 1950) is a
good bet and there's a lot of it around, ...

Oh, yes. Who was it, Ted Edwards, maybe, who called it OCS, for Old
Chevy Spring.

Bob

Don Foreman wrote:
On Tue, 07 Dec 2010 16:56:02 -0500, Bob Engelhardt
wrote:

My question is: is mild steel OK to use for a wrench?

Often it is, particularly for special wrenches that don't get a lot of
use and aren't stressed hard when they do get used. I've made a
number of wrenches out of mild steel.
...

You remind me of some dedicated open-end wrenches that I've made for the
arbor of my horizontal mill. Mild steel, but beefy. Also made pin
spanner wrenches for similar dedicated purposes. All mild steel and
never any problems.

Thanks,
Bob

It would be an interesting challenge to make these, but I have lots of
other interesting challenges that I'd rather do. So, I'm just going to
get a set of 8 point sockets and keep this technique in mind in case
some particular need arises.

Thanks for the replies,
Bob