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.

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
Roger Shoaf
 
Posts: n/a
Default Spring temper question.

At what temperature does a music wire spring lose it's temper?

--
Roger Shoaf
If you are not part of the solution, you are not dissolved in the solvent.


  #2   Report Post  
Ian Stirling
 
Posts: n/a
Default Spring temper question.

Roger Shoaf wrote:
At what temperature does a music wire spring lose it's temper?


Some temperature over 150C or so.

--
http://inquisitor.i.am/ | | Ian Stirling.
---------------------------+-------------------------+--------------------------
"Looks like his brainwaves crash a little short of the beach..." - Duckman.
  #3   Report Post  
Ed Huntress
 
Posts: n/a
Default Spring temper question.

"Roger Shoaf" wrote in message
...
At what temperature does a music wire spring lose it's temper?


Not to be difficult about it, but a music wire spring has no temper, unless
it's been heat treated. Music wire is not heat treated, and it's not normal
practice to heat treat it.

It gains its hardness and strength from being drawn through wire dies --
through work hardening, in other words. Home made music wire springs are
usually wound in that condition, with no heat treating involved.

However, maybe what you want know is how much you can heat it before it
begins to lose its hardness. In an important sense, it never loses the
stiffness of its spring resistance, by the way. The steel has the same
stiffness whether it's hard or soft. But softening it lowers its yield
strength, so it *does* lose its ability to take a load. You can easily
exceed the yield strength of a soft-steel spring, and it won't recover its
original length when you take the load off after that.

Music wire is plain, high-carbon steel, and so it begins to lose hardness at
a low temperatu around 280 deg. F. It progressively loses more hardness
as you heat it up to the range of 700 deg. F or so.

Ed Huntress


  #5   Report Post  
Roger Shoaf
 
Posts: n/a
Default Spring temper question.

Ed

The reason I was asking this question is because I was involved in a
discussion about building a coffee roasting drum to be used in a gas BBQ
grill and it was suggested that a music wire cotter pin might be used in
it's design.

When I built my roasting drum I considered using a spring for the door latch
but opted not to as I was worried about the reliability in an environment
that you are shooting for a 500 F temp.

Seems to me you have confirmed this.

Thanks.

--
Roger Shoaf
If you are not part of the solution, you are not dissolved in the solvent.

"Ed Huntress" wrote in message
news
"Roger Shoaf" wrote in message
...
At what temperature does a music wire spring lose it's temper?


Not to be difficult about it, but a music wire spring has no temper,

unless
it's been heat treated. Music wire is not heat treated, and it's not

normal
practice to heat treat it.

It gains its hardness and strength from being drawn through wire dies --
through work hardening, in other words. Home made music wire springs are
usually wound in that condition, with no heat treating involved.

However, maybe what you want know is how much you can heat it before it
begins to lose its hardness. In an important sense, it never loses the
stiffness of its spring resistance, by the way. The steel has the same
stiffness whether it's hard or soft. But softening it lowers its yield
strength, so it *does* lose its ability to take a load. You can easily
exceed the yield strength of a soft-steel spring, and it won't recover its
original length when you take the load off after that.

Music wire is plain, high-carbon steel, and so it begins to lose hardness

at
a low temperatu around 280 deg. F. It progressively loses more hardness
as you heat it up to the range of 700 deg. F or so.

Ed Huntress






  #6   Report Post  
Ken Vale
 
Posts: n/a
Default Spring temper question.

Ed Huntress wrote:

Because drawing hardens the steel without coarsening the grain, and because
some of the tensile strength comes from the grain alignment resulting from
successive draws through wire-drawing dies, the properties of the thinner
grades can't be duplicated by heat-treating it. The delivered condition,
as-is, is as good as it's going to get.

I sort of understand how heat-treating hardens steel. So my question
is how/why does drawing harden steel? And for that matter how/why does
something work harden?
Ken

  #7   Report Post  
Ed Huntress
 
Posts: n/a
Default Spring temper question.

"Roger Shoaf" wrote in message
...
Ed

The reason I was asking this question is because I was involved in a
discussion about building a coffee roasting drum to be used in a gas BBQ
grill and it was suggested that a music wire cotter pin might be used in
it's design.

When I built my roasting drum I considered using a spring for the door

latch
but opted not to as I was worried about the reliability in an environment
that you are shooting for a 500 F temp.

Seems to me you have confirmed this.


Yeah, music wire would not be a good choice, unless it doesn't matter if
it's quickly softened. If you need real hardness at that temperature (and
I'm guessing that you don't really need very much), high-speed steel is the
solution. That's a little extreme, but it will hold its full hardness up to
around 1,000 deg. F.

There aren't many steels that make good high-temperature springs. But the
application doesn't sound very demanding, so you'll get it solved without
too much trouble.

Good luck.

Ed Huntress


  #8   Report Post  
Ed Huntress
 
Posts: n/a
Default Spring temper question.

"Ken Vale" wrote in message
ogers.com...
Ed Huntress wrote:

Because drawing hardens the steel without coarsening the grain, and

because
some of the tensile strength comes from the grain alignment resulting

from
successive draws through wire-drawing dies, the properties of the thinner
grades can't be duplicated by heat-treating it. The delivered condition,
as-is, is as good as it's going to get.

I sort of understand how heat-treating hardens steel. So my question
is how/why does drawing harden steel? And for that matter how/why does
something work harden?
Ken


That's a good question. The answer is that drawing, like most forms of
hardening (including much of heat-treating) adds strength by creating strain
between the grains. I won't try to elaborate on this here because it's worth
a chapter or two of a book. You can find a better explanation in any
introductory metallurgy book, even the non-mathematical, practical ones that
are used for teaching it as technology, rather than as science.

Ed Huntress


  #9   Report Post  
wws
 
Posts: n/a
Default Spring temper question.


"Ed Huntress" wrote in message
t...
"Roger Shoaf" wrote in message
...
Ed

The reason I was asking this question is because I was involved in a
discussion about building a coffee roasting drum to be used in a gas

BBQ
grill and it was suggested that a music wire cotter pin might be

used in
it's design.

When I built my roasting drum I considered using a spring for the

door
latch
but opted not to as I was worried about the reliability in an

environment
that you are shooting for a 500 F temp.

Seems to me you have confirmed this.


Yeah, music wire would not be a good choice, unless it doesn't matter

if
it's quickly softened. If you need real hardness at that temperature

(and
I'm guessing that you don't really need very much), high-speed steel

is the
solution. That's a little extreme, but it will hold its full hardness

up to
around 1,000 deg. F.

There aren't many steels that make good high-temperature springs. But

the
application doesn't sound very demanding, so you'll get it solved

without
too much trouble.

Good luck.

Ed Huntress


Sometime you just want to ... scream.
Just when it was getting good too.

Note to self: put the spring on the outside.
g

wws


  #10   Report Post  
Ted Edwards
 
Posts: n/a
Default Spring temper question.

wws wrote:

"Ed Huntress" wrote in message


grill and it was suggested that a music wire cotter pin might be

used in
it's design.


Yeah, music wire would not be a good choice, unless it doesn't matter

if
it's quickly softened. If you need real hardness at that temperature

(and
I'm guessing that you don't really need very much), high-speed steel

is the
solution. That's a little extreme, but it will hold its full hardness

up to
around 1,000 deg. F.


Note that a convenient source for the pin might be a broken or dull,
small size HSS drill.

Ted




  #11   Report Post  
mike
 
Posts: n/a
Default Spring temper question.

Ed Huntress wrote:
"Ken Vale" wrote in message
ogers.com...

Ed Huntress wrote:


Because drawing hardens the steel without coarsening the grain, and


because

some of the tensile strength comes from the grain alignment resulting


from

successive draws through wire-drawing dies, the properties of the thinner
grades can't be duplicated by heat-treating it. The delivered condition,
as-is, is as good as it's going to get.


I sort of understand how heat-treating hardens steel. So my question
is how/why does drawing harden steel? And for that matter how/why does
something work harden?
Ken



That's a good question. The answer is that drawing, like most forms of
hardening (including much of heat-treating) adds strength by creating strain
between the grains. I won't try to elaborate on this here because it's worth
a chapter or two of a book. You can find a better explanation in any
introductory metallurgy book, even the non-mathematical, practical ones that
are used for teaching it as technology, rather than as science.

Ed Huntress



Can you recommend a couple of titles or authors that might be found at
the library?
Every time I looked into the subject, I got lost in the science and
didn't learn anything practical.
Thanks, mike

--
Bunch of stuff For Sale and Wanted at the link below.
laptops and parts Test Equipment
4in/400Wout ham linear amp.
Honda CB-125S
400cc Dirt Bike 2003 miles $550
Police Scanner, Color LCD overhead projector
Tek 2465 $800, ham radio, 30pS pulser
Tektronix Concept Books, spot welding head...
http://www.geocities.com/SiliconValley/Monitor/4710/

  #14   Report Post  
Ed Huntress
 
Posts: n/a
Default Spring temper question.

"Fdmorrison" wrote in message
...

I won't try to elaborate on this here because it's worth
a chapter or two of a book. You can find a better explanation in any
introductory metallurgy book, even the non-mathematical, practical ones

that
are used for teaching it as technology, rather than as science.


I wish those texts didn't make a distinction between technology and

science.
So much for books.


Well, for textbook purposes, the books written for "technology" programs are
either qualitative, in which case they don't use math at all; or they're
quantitive, but without the use of calculus or other math that most people
don't learn in high school.

I prefer the books written for technology programs, rather than the
engineering-program versions, in many cases. Anything I'm interested in
usually is well covered that way. For example, the courses I had in statics
and mechanics were non-calculus courses (I took them years after college),
and I got everything I wanted out of them. It was just to satisfy my hobby
interest. I wasn't looking for a brain workout with abstraction and rigor.


When I learned basic blacksmithing, I was taught that once you changed the
iron's(steel's) shape the grain (molecular) structure got stressed, so to
relieve this the iron is heated and allowed to cool (aneal), even for mild
steel.
So in the changing of shape in drawing, there's a similar stress

(hardening)
added to the steel?


Yes, drawing is just one way of work-hardening. It's usually the best way to
gain the greatest unidirectional tensile strength in a material. It also
gives you the best combination of toughness and hardness in many cases.

Keep in mind that the strength and hardness of most metals are directly
related. In the case of steel, they actually publish tables that relate
Brinell hardness to tensile strength.

They assume that the steel is hardened as well as it can be for those
tables. In other words, they assume that you haven't overheated the metal
and caused a lot of grain growth. If the metal has been cold-worked with a
hammer or a press, they assume that you didn't exceed the ultimate
compression strength in the process of hammering, which will cause cracks
and other faults. If you either heat-treat or work-harden badly, you'll have
the local hardness, but not the strength in the whole mass that you should
have.

--
Ed Huntress
(remove "3" from email address for email reply)


  #15   Report Post  
Ed Huntress
 
Posts: n/a
Default Spring temper question.

"mike" wrote in message ...
Ed Huntress wrote:
"Ken Vale" wrote in message
ogers.com...

Ed Huntress wrote:


Because drawing hardens the steel without coarsening the grain, and

because

some of the tensile strength comes from the grain alignment resulting

from

successive draws through wire-drawing dies, the properties of the

thinner
grades can't be duplicated by heat-treating it. The delivered

condition,
as-is, is as good as it's going to get.


I sort of understand how heat-treating hardens steel. So my question
is how/why does drawing harden steel? And for that matter how/why does
something work harden?
Ken



That's a good question. The answer is that drawing, like most forms of
hardening (including much of heat-treating) adds strength by creating

strain
between the grains. I won't try to elaborate on this here because it's

worth
a chapter or two of a book. You can find a better explanation in any
introductory metallurgy book, even the non-mathematical, practical ones

that
are used for teaching it as technology, rather than as science.

Ed Huntress



Can you recommend a couple of titles or authors that might be found at
the library?
Every time I looked into the subject, I got lost in the science and
didn't learn anything practical.
Thanks, mike

--
Bunch of stuff For Sale and Wanted at the link below.
laptops and parts Test Equipment
4in/400Wout ham linear amp.
Honda CB-125S
400cc Dirt Bike 2003 miles $550
Police Scanner, Color LCD overhead projector
Tek 2465 $800, ham radio, 30pS pulser
Tektronix Concept Books, spot welding head...
http://www.geocities.com/SiliconValley/Monitor/4710/


It's been a while since I've read one, but other people have told me that
_Metallurgy Fundamentals_ by Brandt and Warner is a very good
technology-level book. You can get a look at the inside on Amazon to see if
it's what you're looking for. At $43, you'll want to be sure, but there is a
paperback edition, I think.

Another one that I refer to often doesn't sound like a metallurgy book, but
it does cover steel at a practical level. It's called _Tool Steel
Simplified_. It's been in print for many decades but I don't know if it
still is. However, it's a book that your local library probably could find
at some local or community college and could get for you on an interlibrary
loan. That's how I get a lot of expensive books.

In the case of _Metallurgy Fundamentals_, you may want to just select the
subjects that interest you. In the case of _Tool Steel Simplified_, it's
worth going through the whole book. You'll come away with a very good
practical understanding of steel. But I'll bet you would from reading the
steel sections of _Metallurgy Fundamentals_, too.

Good luck. Metallurgy is a lot more interesting than it sounds. g

Ed Huntress




  #16   Report Post  
Ed Huntress
 
Posts: n/a
Default Spring temper question.

"Tom Quackenbush" wrote in message
...

Amazon doesn't list any current printings, but they do offer
several used copies. I just ordered one (1960? printing) a couple of
days ago, based on Ed's recommendation from a year or two ago. I'm
looking forward to reading it.

Ed - I think I remember reading a post of yours where you stressed
the importance of maintaining the tempering temperature for several
hours. I may be mis-remembering & I can't find the post.

I'm wondering how this would affect "selective" (I don't know the
right word) tempering - as in applying a torch to the spine of a knife
blade in order to produce a hardness gradient from the spine to the
edge. Does this work at all, or is it counter-productive? Does it work
better with "forgiving" type steels (say, O-1 or simple carbon
steels)? Given the specific application of scarifying blades for a box
scraper, would I be better off wear facing the blades rather than
relying on tempering to achieve a hard face and softer, springy back?

Also, how much are you charging per answer? g


They're still free, but you're left on your own to get confirmation. g

Hokay...selective tempering is something that has to be done quickly, and
the tradeoff is that you can't gain the benefits of prolonged tempering --
unless you count extended tempering at the *lowest* tempering temperature
you're using. For example, you could soften the back of the blade and not
quite raise the edge temperature to its final tempering temperature, and
then throw it in your kitchen oven at the lowest tempering temperature for
an extended time. It's the hardest part of the blade (the cutting edge)
that's going to benefit most from this treatment, anyway, so it would work
out pretty well, I think.

As for the true value of using this selective, or differential tempering,
the knife people and blacksmiths will know more about it. It's not a trick
that comes from industrial heat-treating. (There is some selective
normalizing and annealing done in industry, however; hammer faces are an
example, where the center is left hard and a ring around the edge of the
face is partially annealed.) I hear that it works and it should be Ok in
theory. But here's something that I think you'll encounter in your new copy
of TSS: the highest possible "toughness" in high-carbon, low-alloy steels
occurs in steel that's been given an extended temper (several hours) at some
temperature in the range of 350 - 375 deg. F. Impact strength is not the
same thing as flexing strength, however, so beware of different definitions
of "toughness" within different metalworking fields.

About your box scraper blades and hard facing: it's not something I've ever
tried, and I've gotten some pretty poor results trying to hard-face
high-carbon steel with Stellite, so I don't do it. Ernie or one of the other
weldors probably can tell you better.


--
Ed Huntress
(remove "3" from email address for email reply)


  #17   Report Post  
Simon
 
Posts: n/a
Default Spring temper question.


"Tom Quackenbush" wrote in message
...

I'm wondering how this would affect "selective" (I don't know the
right word) tempering - as in applying a torch to the spine of a knife
blade in order to produce a hardness gradient from the spine to the
edge. Does this work at all, or is it counter-productive? Does it work
better with "forgiving" type steels (say, O-1 or simple carbon
steels)? Given the specific application of scarifying blades for a box
scraper, would I be better off wear facing the blades rather than
relying on tempering to achieve a hard face and softer, springy back?
Tom Q.


Tom,

There's a slightly better way of selective tempering and a few little tricks
you can use, most important is to do a full temper first to the correct heat
for the RC that you want the edge to be. Once this is done, there's a few
ways of producing a selective temper, the simplest and not requiring
technical know-how is to preheat a reasonable sized piece of steel, big
enough to lay the spine on and not so small that it loses it's heat too
quickly. Take it out and lay the spine of the edge tool on the hot metal and
watch till the straw colour approaches the blade edge (a good way to lose a
hamon though :-( ....) . Heat protecting gels just applied to the edge can
also help. it's a lot more controllable than the method you described with
direct torch heat. The other method is to build a small toaster device that
only the back of the blade sits in, only worth doing if you are planning on
doing lots of selective tempering.
got a link to a knife manufacturer's FAQ that uses selective tempering on
their blades, you might find it interesting.:
http://www.mdk.idv.tw/mdkfaq.htm#3.11

Simon


  #18   Report Post  
Simon
 
Posts: n/a
Default Spring temper question.



Ok, I'll bite - whats a hamon?


Heat treatment line most often associated with japanese swords and clay
hardening techniques



  #19   Report Post  
Simon
 
Posts: n/a
Default Spring temper question.

here's a few examples

http://www.bladegallery.com/knives/k...=small&alt=one

http://www.knives.com/claytemp.html his method is actually not the most
economical or traditional ... the japanese actually scrape away the edge
rather than put the pattern on as they apply the clay

http://home.earthlink.net/~steinrl/terms/terms.htm


  #20   Report Post  
Ed Huntress
 
Posts: n/a
Default Spring temper question.

"Tom Quackenbush" wrote in message
...

If I end up going that route I'd probably farm it out to a local
welder - I haven't picked up a stick in 20 years. Advice from the
r.c.m welders would be very welcome, though. I'd like to understqnd
the process even if I don't do the work myself. Here's a blurb from
the Navy on wearfacing:

http://www.globalsecurity.org/milita.../14250_ch6.pdf

Very interesting. I never saw that explanation of sweating with a
carburizing flame before. That explains a few things.

Maybe I'll try hardfacing again, armed with that information. Thanks, Tom.

--
Ed Huntress
(remove "3" from email address for email reply)




  #21   Report Post  
Gunner
 
Posts: n/a
Default Spring temper question.

On Thu, 02 Oct 2003 06:53:51 -0400, Tom Quackenbush
wrote:


Ok, I'll bite - whats a hamon?

R,
Tom Q.


The wavey line one sees on the blade of Japanese edged weapons. Usually
as a result of the blade being partially wrapped in clay

Gunner

Cum catapultae proscriptae erunt tum soli proscript catapultas habebunt.
  #22   Report Post  
Ed Huntress
 
Posts: n/a
Default Spring temper question.

"Tom Quackenbush" wrote in message
...
On Thu, 02 Oct 2003 12:55:53 GMT, "Ed Huntress"
wrote:

"Tom Quackenbush" wrote:

SNIP
Here's a blurb from the Navy on wearfacing:


http://www.globalsecurity.org/milita...tc/14250_ch6.p

df

Very interesting. I never saw that explanation of sweating with a
carburizing flame before. That explains a few things.

Maybe I'll try hardfacing again, armed with that information. Thanks,

Tom.

I posted that link by mistake ( I meant to post the link to chapter
7) and hadn't read it until seeing your comment. You're right, that is
interesting.

I'd be interested in your results if you try it.


I'll let you know. I weld out in my unheated garage, and it's pretty cold
right now, so it may be a while. g

Here's the thing that struck me about the "sweating" business, something I
hadn't thought about befo High-carbon steel melts at a slightly lower
temperature than low-carbon steel. So, if you carburize the surface a bit
with a carburizing flame, you wind up melting a thin layer on the surface of
the steel first. If I understand the article correctly, that provides as
sort of flux, or a molten interface at least, that helps the hardfacing
material to flow and bond.

I never raised the temperature of the steel I tried to hardface quite to
that temperature. Thus, I never got good results.

At least, that's what I gather from the article.

--
Ed Huntress
(remove "3" from email address for email reply)


Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Simple question regarding Ceiling tiles and sound? lbbs UK diy 5 March 26th 04 02:36 AM
Plumbing Question Jeff UK diy 4 December 1st 03 02:49 PM
Pipe thread question, NPT vs NPSF, MIP, FIP and IPS Jeff Wisnia Metalworking 1 August 9th 03 05:20 AM


All times are GMT +1. The time now is 06:08 PM.

Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 DIYbanter.
The comments are property of their posters.
 

About Us

"It's about DIY & home improvement"