spoke fatigue troll

Ben C

On 2008-05-04, jim beam <spamvortex@bad.example.net> wrote:
>> On 2008-05-01, jobst.brandt@stanfordalumni.org <jobst.brandt@stanfordalumni.org> wrote:
[...]
>>> Hole deformation is an asymptotic effect that with reasonable spoke
>>> tension is already as deep as it will get.

[...]
> it evidences a fundamental misunderstanding [or fundamental retardation]
> to claim that increasing spoke tension doesn't additionally indent a
> hub's spoke holes.
>
> brinell hardness # = P/pi.D.t
>
> where P = indenter load, D = indenter ball diameter and t = depth of
> impression.
>
> from there, you don't have to be enrico fermi to correlate increasing
> indenter load with increasing indenter depth. do you.

Just to get this clear, brinell hardness # is constant for a given
material right?

Therefore depth of impression is proportional to indenter load.

Not sure exactly what Jobst means by "asymptotic" but I thought they
were saying that depth of impression increased by rapidly less and less
as load was increased?

Tom Sherman

"jim beam" wrote:
> Tom Sherman wrote:
>> "jim beam" wrote:
>>> Ben C wrote:
>>>> On 2008-05-02, Peter Cole <peter_cole@verizon.net> wrote:
>>>>> jobst.brandt@stanfordalumni.org wrote:
>>>>>> Stress relief.
>>>>>>
>>>>>> I think deformation of flange holes in aluminum hubs is being
>>>>>> mis-characterized, leading to incorrect assumptions about effective
>>>>>> spoke hole position before and after stress relieving and that
>>>>>> trueness of the wheel suffers from the process.
>>>>>>
>>>>>> Hole deformation is an asymptotic effect that with reasonable spoke
>>>>>> tension is already as deep as it will get. If that were not so,
>>>>>> spokes would gradually sink through the flange and pull out. Once
>>>>>> about a third of the spoke diameter bears fully on the flange hole it
>>>>>> is as deep as it will go while subsequent stress relief cannot "bed
>>>>>> them in" any deeper as the process is often depicted here. The terms
>>>>>> bedding in or stabilizing are a misnomers chosen by people who cannot
>>>>>> visualize mechanical stress relief or that spokes bed in naturally
>>>>>> from initial spoke tension.
>>>>> The Rockwell hardness test (B scale, used for materials like
>>>>> aluminum) uses a 1/16" (1.6mm) steel ball and measures the depth
>>>>> indented with 100kgf. Typical hardness numbers for aluminum would
>>>>> indicate a depth of around 0.14mm (into a flat surface of
>>>>> reasonable thickness). While the scenario is a bit different, the
>>>>> dimensions and forces are similar. Given that the spoke and hole
>>>>> diameters are close and the angle is small, it seems that the
>>>>> absolute "bedding in" is small and happens early (with tension).
>>>>> From there it seems safe to assume that stress relief doesn't cause
>>>>> any significant additional "bedding in".
>>>>>
>>>>> Perhaps this issue is finally put to bed.
>>>>
>>>> I'm not quite ready to put it to bed yet.
>>>>
>>>> The most likely explanation in my mind is that during stabilization the
>>>> spoke cuts into a new part of the hub flange (the outside edge of the
>>>> hole probably) that it wasn't quite bearing on before. The parts it's
>>>> already been pulled against by tensioning don't deform any further for
>>>> the reasons you state.
>>>
>>> this is /so/ basic. if you increase the force, you get a bigger
>>> indentation. all you have to do is look at the formula:
>>> http://www.key-to-steel.com/Articles/Art140.htm [...]
>>>
>> Does not the area deformed during initial tensioning work harden, and
>> would that not reduce the deformation from spoke squeezing?
>>
>
> why do you think hardness numbers are comparatively, not quantitatively
> correlated with strength?
>
For different materials obviously, but for the same material?

--
Tom Sherman - Holstein-Friesland Bovinia
The weather is here, wish you were beautiful

Tom Sherman

"jim beam" wrote:
> Tom Sherman wrote:
>> "jim beam" wrote:
>>> [...]
>>> nothing like the mental deformation we see from so-called "engineers"
>>
>> Well, they are not "so-called" if granted a PE by a licensing board.
>>
>> What is your professional registration?
>>
>>> when they doggedly try to justify their underinformed misconceptions.
>>
>> No hint of resentment here, eh?
>>
>
> refusing to address the "engineering" then tom? shouldn't be too hard
> for a "professional" to do. unless they're a lightweight of course.

"jim" refuses to answer the question - does "he" have any professional
registration?

--
Tom Sherman - Holstein-Friesland Bovinia
The weather is here, wish you were beautiful

jim beam

Ben C wrote:
> On 2008-05-04, jim beam <spamvortex@bad.example.net> wrote:
>>> On 2008-05-01, jobst.brandt@stanfordalumni.org <jobst.brandt@stanfordalumni.org> wrote:
> [...]
>>>> Hole deformation is an asymptotic effect that with reasonable spoke
>>>> tension is already as deep as it will get.
>
> [...]
>> it evidences a fundamental misunderstanding [or fundamental retardation]
>> to claim that increasing spoke tension doesn't additionally indent a
>> hub's spoke holes.
>>
>> brinell hardness # = P/pi.D.t
>>
>> where P = indenter load, D = indenter ball diameter and t = depth of
>> impression.
>>
>> from there, you don't have to be enrico fermi to correlate increasing
>> indenter load with increasing indenter depth. do you.
>
> Just to get this clear, brinell hardness # is constant for a given
> material right?

right.

>
> Therefore depth of impression is proportional to indenter load.

and thus, a spoke subject to higher load will more deeply embed in a hub
hole. which in turn means that if we subject a spoke to loads as high
or higher than those seen in service, we will not have a wheel go out of
true in use - the /true/ purpose of this ancient practice.


>
> Not sure exactly what Jobst means by "asymptotic" but I thought they
> were saying that depth of impression increased by rapidly less and less
> as load was increased?

he's trying to play on the nature of the indenter being spherical. but
that in turn shows he never bothered to actually read about hardness
testing, just make superficial presumption.

jim beam

Tom Sherman wrote:
> "jim beam" wrote:
>> Tom Sherman wrote:
>>> "jim beam" wrote:
>>>> [...]
>>>> nothing like the mental deformation we see from so-called "engineers"
>>>
>>> Well, they are not "so-called" if granted a PE by a licensing board.
>>>
>>> What is your professional registration?
>>>
>>>> when they doggedly try to justify their underinformed misconceptions.
>>>
>>> No hint of resentment here, eh?
>>>
>>
>> refusing to address the "engineering" then tom? shouldn't be too hard
>> for a "professional" to do. unless they're a lightweight of course.
>
> "jim" refuses to answer the question - does "he" have any professional
> registration?
>

you want a sock puppet to answer? are you some kind of retard?

discuss the engineering, s/n < 1:100 goddamned lightweight.

jim beam

Tom Sherman wrote:
> "jim beam" wrote:
>> Tom Sherman wrote:
>>> "jim beam" wrote:
>>>> Ben C wrote:
>>>>> On 2008-05-02, Peter Cole <peter_cole@verizon.net> wrote:
>>>>>> jobst.brandt@stanfordalumni.org wrote:
>>>>>>> Stress relief.
>>>>>>>
>>>>>>> I think deformation of flange holes in aluminum hubs is being
>>>>>>> mis-characterized, leading to incorrect assumptions about effective
>>>>>>> spoke hole position before and after stress relieving and that
>>>>>>> trueness of the wheel suffers from the process.
>>>>>>>
>>>>>>> Hole deformation is an asymptotic effect that with reasonable spoke
>>>>>>> tension is already as deep as it will get. If that were not so,
>>>>>>> spokes would gradually sink through the flange and pull out. Once
>>>>>>> about a third of the spoke diameter bears fully on the flange
>>>>>>> hole it
>>>>>>> is as deep as it will go while subsequent stress relief cannot "bed
>>>>>>> them in" any deeper as the process is often depicted here. The
>>>>>>> terms
>>>>>>> bedding in or stabilizing are a misnomers chosen by people who
>>>>>>> cannot
>>>>>>> visualize mechanical stress relief or that spokes bed in naturally
>>>>>>> from initial spoke tension.
>>>>>> The Rockwell hardness test (B scale, used for materials like
>>>>>> aluminum) uses a 1/16" (1.6mm) steel ball and measures the depth
>>>>>> indented with 100kgf. Typical hardness numbers for aluminum would
>>>>>> indicate a depth of around 0.14mm (into a flat surface of
>>>>>> reasonable thickness). While the scenario is a bit different, the
>>>>>> dimensions and forces are similar. Given that the spoke and hole
>>>>>> diameters are close and the angle is small, it seems that the
>>>>>> absolute "bedding in" is small and happens early (with tension).
>>>>>> From there it seems safe to assume that stress relief doesn't
>>>>>> cause any significant additional "bedding in".
>>>>>>
>>>>>> Perhaps this issue is finally put to bed.
>>>>>
>>>>> I'm not quite ready to put it to bed yet.
>>>>>
>>>>> The most likely explanation in my mind is that during stabilization
>>>>> the
>>>>> spoke cuts into a new part of the hub flange (the outside edge of the
>>>>> hole probably) that it wasn't quite bearing on before. The parts it's
>>>>> already been pulled against by tensioning don't deform any further for
>>>>> the reasons you state.
>>>>
>>>> this is /so/ basic. if you increase the force, you get a bigger
>>>> indentation. all you have to do is look at the formula:
>>>> http://www.key-to-steel.com/Articles/Art140.htm [...]
>>>>
>>> Does not the area deformed during initial tensioning work harden, and
>>> would that not reduce the deformation from spoke squeezing?
>>>
>>
>> why do you think hardness numbers are comparatively, not
>> quantitatively correlated with strength?
>>
> For different materials obviously, but for the same material?
>

oh dear, another "engineer" unclear on the concept. i'll ask again,
"why do you think hardness numbers are comparatively, not quantitatively
correlated with strength?".

goddamned lightweight.

Tom Sherman

"jim beam" wrote:
> Tom Sherman wrote:
>> "jim beam" wrote:
>>> Tom Sherman wrote:
>>>> "jim beam" wrote:
>>>>> [...]
>>>>> nothing like the mental deformation we see from so-called "engineers"
>>>>
>>>> Well, they are not "so-called" if granted a PE by a licensing board.
>>>>
>>>> What is your professional registration?
>>>>
>>>>> when they doggedly try to justify their underinformed misconceptions.
>>>>
>>>> No hint of resentment here, eh?
>>>>
>>>
>>> refusing to address the "engineering" then tom? shouldn't be too
>>> hard for a "professional" to do. unless they're a lightweight of
>>> course.
>>
>> "jim" refuses to answer the question - does "he" have any professional
>> registration?
>>
>
> you want a sock puppet to answer? are you some kind of retard?
>
> discuss the engineering, s/n < 1:100 goddamned lightweight.

"jim's" silence is deafening.

--
Tom Sherman - Holstein-Friesland Bovinia
The weather is here, wish you were beautiful

daveornee

As the spoke indents further up to half it's diameter the surface area involved gets larger, thus the force/penetration is not linearly proportional.
When Peter Cole mentioned .75 mm earlier in this thread (about 1/3 diameter of a 2.0 mm diameter spoke) it seemed likely that going past that depth would be unlikely as the load required would be significantly more than experienced in wheels ridden in the real world. I mostly deal with spokes that have 2.0 mm diameter at the hub and nipple ends. However, there certainly are spokes with 1.8 mm and 2.3 mm diameters that are used.

jim beam

Tom Sherman wrote:
> "jim beam" wrote:
>> Tom Sherman wrote:
>>> "jim beam" wrote:
>>>> Tom Sherman wrote:
>>>>> "jim beam" wrote:
>>>>>> [...]
>>>>>> nothing like the mental deformation we see from so-called "engineers"
>>>>>
>>>>> Well, they are not "so-called" if granted a PE by a licensing board.
>>>>>
>>>>> What is your professional registration?
>>>>>
>>>>>> when they doggedly try to justify their underinformed misconceptions.
>>>>>
>>>>> No hint of resentment here, eh?
>>>>>
>>>>
>>>> refusing to address the "engineering" then tom? shouldn't be too
>>>> hard for a "professional" to do. unless they're a lightweight of
>>>> course.
>>>
>>> "jim" refuses to answer the question - does "he" have any
>>> professional registration?
>>>
>>
>> you want a sock puppet to answer? are you some kind of retard?
>>
>> discuss the engineering, s/n < 1:100 goddamned lightweight.
>
> "jim's" silence is deafening.
>

goddamned hypocrite!!!!!!!!

goddamned lightweight.

Tom Sherman

"jim beam" wrote:
> Tom Sherman wrote:
>> "jim beam" wrote:
>>> Tom Sherman wrote:
>>>> "jim beam" wrote:
>>>>> Ben C wrote:
>>>>>> On 2008-05-02, Peter Cole <peter_cole@verizon.net> wrote:
>>>>>>> jobst.brandt@stanfordalumni.org wrote:
>>>>>>>> Stress relief.
>>>>>>>>
>>>>>>>> I think deformation of flange holes in aluminum hubs is being
>>>>>>>> mis-characterized, leading to incorrect assumptions about effective
>>>>>>>> spoke hole position before and after stress relieving and that
>>>>>>>> trueness of the wheel suffers from the process.
>>>>>>>>
>>>>>>>> Hole deformation is an asymptotic effect that with reasonable spoke
>>>>>>>> tension is already as deep as it will get. If that were not so,
>>>>>>>> spokes would gradually sink through the flange and pull out. Once
>>>>>>>> about a third of the spoke diameter bears fully on the flange
>>>>>>>> hole it
>>>>>>>> is as deep as it will go while subsequent stress relief cannot "bed
>>>>>>>> them in" any deeper as the process is often depicted here. The
>>>>>>>> terms
>>>>>>>> bedding in or stabilizing are a misnomers chosen by people who
>>>>>>>> cannot
>>>>>>>> visualize mechanical stress relief or that spokes bed in naturally
>>>>>>>> from initial spoke tension.
>>>>>>> The Rockwell hardness test (B scale, used for materials like
>>>>>>> aluminum) uses a 1/16" (1.6mm) steel ball and measures the depth
>>>>>>> indented with 100kgf. Typical hardness numbers for aluminum would
>>>>>>> indicate a depth of around 0.14mm (into a flat surface of
>>>>>>> reasonable thickness). While the scenario is a bit different, the
>>>>>>> dimensions and forces are similar. Given that the spoke and hole
>>>>>>> diameters are close and the angle is small, it seems that the
>>>>>>> absolute "bedding in" is small and happens early (with tension).
>>>>>>> From there it seems safe to assume that stress relief doesn't
>>>>>>> cause any significant additional "bedding in".
>>>>>>>
>>>>>>> Perhaps this issue is finally put to bed.
>>>>>>
>>>>>> I'm not quite ready to put it to bed yet.
>>>>>>
>>>>>> The most likely explanation in my mind is that during
>>>>>> stabilization the
>>>>>> spoke cuts into a new part of the hub flange (the outside edge of the
>>>>>> hole probably) that it wasn't quite bearing on before. The parts it's
>>>>>> already been pulled against by tensioning don't deform any further
>>>>>> for
>>>>>> the reasons you state.
>>>>>
>>>>> this is /so/ basic. if you increase the force, you get a bigger
>>>>> indentation. all you have to do is look at the formula:
>>>>> http://www.key-to-steel.com/Articles/Art140.htm [...]
>>>>>
>>>> Does not the area deformed during initial tensioning work harden,
>>>> and would that not reduce the deformation from spoke squeezing?
>>>>
>>>
>>> why do you think hardness numbers are comparatively, not
>>> quantitatively correlated with strength?
>>>
>> For different materials obviously, but for the same material?
>>
>
> oh dear, another "engineer" unclear on the concept. i'll ask again,
> "why do you think hardness numbers are comparatively, not quantitatively
> correlated with strength?".
>
That is irrelevant to the question at hand. In either case, work
hardening of the hub flange at the spoke holes will reduce the amount of
plastic deformation for a given future applied load, no?

> goddamned lightweight.

You have keyboard macro's for insults?

--
Tom Sherman - Holstein-Friesland Bovinia
The weather is here, wish you were beautiful

Tom Sherman

"jim beam" wrote:
> Tom Sherman wrote:
>> "jim beam" wrote:
>>> Tom Sherman wrote:
>>>> "jim beam" wrote:
>>>>> Tom Sherman wrote:
>>>>>> "jim beam" wrote:
>>>>>>> [...]
>>>>>>> nothing like the mental deformation we see from so-called
>>>>>>> "engineers"
>>>>>>
>>>>>> Well, they are not "so-called" if granted a PE by a licensing board.
>>>>>>
>>>>>> What is your professional registration?
>>>>>>
>>>>>>> when they doggedly try to justify their underinformed
>>>>>>> misconceptions.
>>>>>>
>>>>>> No hint of resentment here, eh?
>>>>>>
>>>>>
>>>>> refusing to address the "engineering" then tom? shouldn't be too
>>>>> hard for a "professional" to do. unless they're a lightweight of
>>>>> course.
>>>>
>>>> "jim" refuses to answer the question - does "he" have any
>>>> professional registration?
>>>>
>>>
>>> you want a sock puppet to answer? are you some kind of retard?
>>>
>>> discuss the engineering, s/n < 1:100 goddamned lightweight.
>>
>> "jim's" silence is deafening.
>>
>
> goddamned hypocrite!!!!!!!!
>
> goddamned lightweight.

Note "jim's" continued refusal to answer the question.

--
Tom Sherman - Holstein-Friesland Bovinia
The weather is here, wish you were beautiful

Ben C

On 2008-05-03, Peter Cole <peter_cole@verizon.net> wrote:
> Ben C wrote:
>> On 2008-05-02, Peter Cole <peter_cole@verizon.net> wrote:
>
>>> The Rockwell hardness test (B scale, used for materials like aluminum)
>>> uses a 1/16" (1.6mm) steel ball and measures the depth indented with
>>> 100kgf. Typical hardness numbers for aluminum would indicate a depth of
>>> around 0.14mm (into a flat surface of reasonable thickness). While the
>>> scenario is a bit different, the dimensions and forces are similar.
>>> Given that the spoke and hole diameters are close and the angle is
>>> small, it seems that the absolute "bedding in" is small and happens
>>> early (with tension). From there it seems safe to assume that stress
>>> relief doesn't cause any significant additional "bedding in".
>>>
>>> Perhaps this issue is finally put to bed.
>>
>> I'm not quite ready to put it to bed yet.
>>
>> The most likely explanation in my mind is that during stabilization the
>> spoke cuts into a new part of the hub flange (the outside edge of the
>> hole probably) that it wasn't quite bearing on before. The parts it's
>> already been pulled against by tensioning don't deform any further for
>> the reasons you state.
>
> I don't see how (when stress relieving) the spoke could make contact
> with parts of the hub it hadn't already contacted with full tension.
> What you seem to be suggesting is either the wall of the hole at the
> flange deforming, or the face of the flange in the vicinity of the hole.

Pretty much.

> I don't see why the first wouldn't have already happened and maxed out
> for the reasons above, and I don't think there's anywhere near the force
> to do the second just from stress relieving. The face of the flange is
> typically angled inward by about the bracing angle, and there must be a
> little spoke overhang or else you couldn't lace it. Stress relieving is
> only going to increase the spoke tension momentarily, nothing more, it
> can't emboss the flange face with that force.
>
> You are postulating new points of forceful contact that occur only when
> stress relieving. I can't see that.

I don't have a precise idea of where these might be, just that
something's got to give, and in daveornee's pictures it looked like the
hub rather than the spoke.

Another thing to consider is that during the "Mavic method" of
stabilization the hub gets displaced along its axis by some amount which
sort of wraps the spokes on the top round the flange, meaning they're
pulling on a slightly different line than before. It's not just a pure
increase in tension, things do move a bit.

jim beam

Tom Sherman wrote:
> "jim beam" wrote:
>> Tom Sherman wrote:
>>> "jim beam" wrote:
>>>> Tom Sherman wrote:
>>>>> "jim beam" wrote:
>>>>>> Ben C wrote:
>>>>>>> On 2008-05-02, Peter Cole <peter_cole@verizon.net> wrote:
>>>>>>>> jobst.brandt@stanfordalumni.org wrote:
>>>>>>>>> Stress relief.
>>>>>>>>>
>>>>>>>>> I think deformation of flange holes in aluminum hubs is being
>>>>>>>>> mis-characterized, leading to incorrect assumptions about
>>>>>>>>> effective
>>>>>>>>> spoke hole position before and after stress relieving and that
>>>>>>>>> trueness of the wheel suffers from the process.
>>>>>>>>>
>>>>>>>>> Hole deformation is an asymptotic effect that with reasonable
>>>>>>>>> spoke
>>>>>>>>> tension is already as deep as it will get. If that were not so,
>>>>>>>>> spokes would gradually sink through the flange and pull out. Once
>>>>>>>>> about a third of the spoke diameter bears fully on the flange
>>>>>>>>> hole it
>>>>>>>>> is as deep as it will go while subsequent stress relief cannot
>>>>>>>>> "bed
>>>>>>>>> them in" any deeper as the process is often depicted here. The
>>>>>>>>> terms
>>>>>>>>> bedding in or stabilizing are a misnomers chosen by people who
>>>>>>>>> cannot
>>>>>>>>> visualize mechanical stress relief or that spokes bed in naturally
>>>>>>>>> from initial spoke tension.
>>>>>>>> The Rockwell hardness test (B scale, used for materials like
>>>>>>>> aluminum) uses a 1/16" (1.6mm) steel ball and measures the depth
>>>>>>>> indented with 100kgf. Typical hardness numbers for aluminum
>>>>>>>> would indicate a depth of around 0.14mm (into a flat surface of
>>>>>>>> reasonable thickness). While the scenario is a bit different,
>>>>>>>> the dimensions and forces are similar. Given that the spoke and
>>>>>>>> hole diameters are close and the angle is small, it seems that
>>>>>>>> the absolute "bedding in" is small and happens early (with
>>>>>>>> tension). From there it seems safe to assume that stress relief
>>>>>>>> doesn't cause any significant additional "bedding in".
>>>>>>>>
>>>>>>>> Perhaps this issue is finally put to bed.
>>>>>>>
>>>>>>> I'm not quite ready to put it to bed yet.
>>>>>>>
>>>>>>> The most likely explanation in my mind is that during
>>>>>>> stabilization the
>>>>>>> spoke cuts into a new part of the hub flange (the outside edge of
>>>>>>> the
>>>>>>> hole probably) that it wasn't quite bearing on before. The parts
>>>>>>> it's
>>>>>>> already been pulled against by tensioning don't deform any
>>>>>>> further for
>>>>>>> the reasons you state.
>>>>>>
>>>>>> this is /so/ basic. if you increase the force, you get a bigger
>>>>>> indentation. all you have to do is look at the formula:
>>>>>> http://www.key-to-steel.com/Articles/Art140.htm [...]
>>>>>>
>>>>> Does not the area deformed during initial tensioning work harden,
>>>>> and would that not reduce the deformation from spoke squeezing?
>>>>>
>>>>
>>>> why do you think hardness numbers are comparatively, not
>>>> quantitatively correlated with strength?
>>>>
>>> For different materials obviously, but for the same material?
>>>
>>
>> oh dear, another "engineer" unclear on the concept. i'll ask again,
>> "why do you think hardness numbers are comparatively, not
>> quantitatively correlated with strength?".
>>
> That is irrelevant to the question at hand. In either case, work
> hardening of the hub flange at the spoke holes will reduce the amount of
> plastic deformation for a given future applied load, no?

of course yes, but if you're unclear on the concept, and if you can't
read the math, then you're a goddamned lightweight if you think it's not
part of the hardness numbers!!!


>
>> goddamned lightweight.
>
> You have keyboard macro's for insults?
>

no, it's lovingly typed out by hand, just for you. and it's an
observation of fact. goddamned lightweight.

jim beam

Tom Sherman wrote:
> "jim beam" wrote:
>> Tom Sherman wrote:
>>> "jim beam" wrote:
>>>> Tom Sherman wrote:
>>>>> "jim beam" wrote:
>>>>>> Tom Sherman wrote:
>>>>>>> "jim beam" wrote:
>>>>>>>> [...]
>>>>>>>> nothing like the mental deformation we see from so-called
>>>>>>>> "engineers"
>>>>>>>
>>>>>>> Well, they are not "so-called" if granted a PE by a licensing board.
>>>>>>>
>>>>>>> What is your professional registration?
>>>>>>>
>>>>>>>> when they doggedly try to justify their underinformed
>>>>>>>> misconceptions.
>>>>>>>
>>>>>>> No hint of resentment here, eh?
>>>>>>>
>>>>>>
>>>>>> refusing to address the "engineering" then tom? shouldn't be too
>>>>>> hard for a "professional" to do. unless they're a lightweight of
>>>>>> course.
>>>>>
>>>>> "jim" refuses to answer the question - does "he" have any
>>>>> professional registration?
>>>>>
>>>>
>>>> you want a sock puppet to answer? are you some kind of retard?
>>>>
>>>> discuss the engineering, s/n < 1:100 goddamned lightweight.
>>>
>>> "jim's" silence is deafening.
>>>
>>
>> goddamned hypocrite!!!!!!!!
>>
>> goddamned lightweight.
>
> Note "jim's" continued refusal to answer the question.
>

are you some kind of retard? where will a "sock puppet" get any kind of
accreditation? muppet university?

and get back to the engineering tom. here, let me replace what you snipped:

"brinell hardness # = P/pi.D.t

where P = indenter load, D = indenter ball diameter and t = depth of
impression."

so, as an "engineer", where's your argument about load and indenter depth?

goddamned lightweight.