# bending metal with heat



## Flaco712 (Oct 10, 2010)

starting my frame wrap soon and i dont understand how heating the metal with a torch and letting it cool on its own would make it that much weaker when the metal is welded it gets cherry red so would that make the welded area weak then or is there any other simple garage tools to bend 1/4''


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## CoupeDTS (Nov 10, 2007)

a sledge and heavy duty c clamps. Weld a spot and c clamp more, weld and c clamp more, and so on. Heat weakens the metal but in the long run youre making that part of the frame stronger


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## AndrewH (Dec 12, 2002)

You'd need to go to a metallurgy website with a tempering section to get the exact low down. 

I use a 'porta powered' c-clamp. I personally never had a need to heat low carbon/mild steel.


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## DARKJUGGERNAUT (Apr 14, 2004)

> _Originally posted by CoupeDTS_@Jan 9 2011, 07:25 PM~19550045
> *a sledge and heavy duty c clamps.  Weld a spot and c clamp more, weld and c clamp more, and so on.  Heat weakens the metal but in the long run youre making that part of the frame stronger
> *


this is how..its part of lowrider 5lb sledge get ur swoll on... :biggrin:


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## OUTHOPU (Feb 24, 2006)

> _Originally posted by Flaco712_@Jan 9 2011, 08:18 PM~19550033
> *starting my frame wrap soon and i dont understand how heating the metal with a torch and letting it cool on its own would make it that much weaker when the metal is welded it gets cherry red so would that make the welded area weak then or is there any other simple garage tools to bend 1/4''
> *


You can heat it if needed as long as you don't quench it you'll be fine. You usually don't need to get the metal red hot to bend it anyways. You only need a little heat to get the steel to relax a little. Just a small rose bud tip is all I use when heating plate for bending into tight or difficult bends. 

I also have a powered hydraulic C clamp, plate bender, and several bessy clamps to make life easier. I still keep a sledge hammer handy just in case.


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## stevie d (Oct 30, 2002)

ive never realy seen why heating steel to bend it would effect its strenght after all you gunna weld along its entire lenght at a million degrees :biggrin:


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## lance_aka_64 (May 23, 2010)

That's why you stitch weld.


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## Purple Haze (Aug 9, 2004)

> _Originally posted by OUTHOPU_@Jan 9 2011, 11:25 PM~19552577
> *You can heat it if needed as long as you don't quench it you'll be fine. You usually don't need to get the metal red hot to bend it anyways. You only need a little heat to get the steel to relax a little.  Just a small rose bud tip is all I use when heating plate for bending into tight or difficult bends.
> 
> I also have a powered hydraulic C clamp, plate bender, and several bessy clamps to make life easier. I still keep a sledge hammer handy just in case.
> *


X2


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## AndrewH (Dec 12, 2002)

Here's an excerpt:

"Heating to the absorption point (1400,melting point is 2600) brings the grain of steel to its finest texture. The higher the heating beyond this point and the lower the carbon, the larger the resulting crystals upon cooling. This may be seen, in many cases, by examining fractured specimens with the unaided eye. This enlargement of crystals reduces strength, hence the size of crystals is a visible sign indicating strength. ...

Steel need never be heated above its absorption point except to have it amply hot for shaping in a single heat. ... However, low-carbon steel escapes injury at high heats in most instances, but becomes brittle if heated repeatedly below 1650° F. It is restored to its elasticity if heated above 1G50° F.

The crystalline structure of a piece of steel as affected by heat is determined by the five conditions as follows:

(1) Temperature, (2) duration of heating, (3) mass, (4) rapidity of cooling, and (5) whether or not steel cools without being rolled, hammered, or otherwise subjected to pressure or impact"

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Does any of this matter when your using as much steel as we do? No. We could be using half as thick high carbon or even alloy steel in half the area,then this type of stuff would matter,but the only advantage would be weight savings.

When I win the lotto I'm having a 4130 frame built just because :biggrin:


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## Hannibal Lector (Oct 10, 2006)

I learned that heat n coolin heat n coolin makes the metal stronger(stiffer) but has a higher chance of having it snapping. Not as flexible. My frend told me this, he's a welder from pearl harbor. I may have explained wrong. Correct me though.


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## rzarock (Sep 13, 2009)

> _Originally posted by Flaco712_@Jan 9 2011, 06:18 PM~19550033
> *starting my frame wrap soon and i dont understand how heating the metal with a torch and letting it cool on its own would make it that much weaker when the metal is welded it gets cherry red so would that make the welded area weak then or is there any other simple garage tools to bend 1/4''
> *


If you’re just using run of the mill low carbon steel you’re fine. You can heat and bend with no problem as long as you don’t heat too much. If it’s sparking and white you’re way too hot. Low carbon steel could also be quenched but I’d just let it air cool. As you start moving up in carbon levels and increasing alloy contents you have to be more concerned with heating and cooling cycles. It gets a lot more complicated. You have to be a lot more careful and there’s post processing that should occur to maintain structural integrity.

As far as the welding goes, that’s a little different. There’s a lot behind it. In general, a weld joint has three areas; the weld bead (fusion zone), the heat affected zone and the unaffected metal. The weld bead is strong when it solidifies. The heat affected zone has been annealed and is weak compared to the weld bead and unaffected metal. That’s why when welded joints fail it typically happens next to the weld bead. Annealing occurs when metal is heated to just below its melting point. It makes the metal softer and more ductile but reduces strength.

The reason low carbon steel is not really affected by heating (annealing) is because it’s already pretty soft and ductile when compared to heat treated alloys. Long story short, you can use heat to bend steel for this application. Just don't over do it.


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## rzarock (Sep 13, 2009)

> _Originally posted by Hannibal Lector_@Jan 10 2011, 03:21 AM~19554088
> *I learned that heat n coolin heat n coolin makes the metal stronger(stiffer) but has a higher chance of having it snapping. Not as flexible. My frend told me this, he's a welder from pearl harbor. I may have explained wrong. Correct me though.
> *


In a nut shell this is how metals are heat treated and yes, the the higher the strength the more brittle the material becomes.


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## DARKJUGGERNAUT (Apr 14, 2004)

> _Originally posted by Hannibal Lector_@Jan 10 2011, 04:21 AM~19554088
> *I learned that heat n coolin heat n coolin makes the metal stronger(stiffer) but has a higher chance of having it snapping. Not as flexible. My frend told me this, he's a welder from pearl harbor. I may have explained wrong. Correct me though.
> *


u thinkin case hardening..?


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## Flaco712 (Oct 10, 2010)

Just an off the wall question what would be a ruff idea in hours to wrap a frame in 1/4 I'm kind running short on time to get it done and I only will have a couple hours a day to do it


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## KAKALAK (Mar 11, 2005)

> _Originally posted by stevie d_@Jan 10 2011, 01:40 AM~19552752
> *ive never realy seen why heating steel to bend it would effect its strenght after all you gunna weld along its entire lenght at a million degrees  :biggrin:
> *


it does weaken it. Its still going to be stronger than the og frame though. Stitch welds are the way to go. Plus holes cut in the reinforcment plates and then welded shut joining the rein. plate to the frame in the middle.


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## Hannibal Lector (Oct 10, 2006)

> _Originally posted by Flaco712_@Jan 10 2011, 10:12 AM~19555470
> *Just an off the wall question what would be a ruff idea in hours to wrap a frame in 1/4 I'm kind running short on time to get it done and I only will have a couple hours a day to do it
> *


It depends on u. By urself or got a fren. But it will take u about a week by urself. Depends how many hours u work on it a day.


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## OUTHOPU (Feb 24, 2006)

> _Originally posted by Flaco712+Jan 10 2011, 12:12 PM~19555470-->
> 
> 
> 
> ...


I'd say it will take far longer than 1 week if it's his first time. It also depends how nice of a job he wants done.


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## Flaco712 (Oct 10, 2010)

i am working on making a heavy duty clamp to help bend the wrap into place as far as welding them in i know my welds will look fine i only have about 2 to 3 hours a day and about a month to do it maybe 2 then its off the get painted


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## ROCK OUT (Jan 7, 2006)

> _Originally posted by Flaco712_@Jan 10 2011, 02:33 PM~19557834
> *i am working on making a heavy duty clamp to help bend the wrap into place as far as welding them in i know my welds will look fine i only have about 2 to 3 hours a day and about a month to do it maybe 2 then its off the get painted
> *


2-3 hours a day for a full frame wrap in a month? your fucked


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## OUTHOPU (Feb 24, 2006)

Use 3/16" instead of 1/4". It's plenty strong enough and it's amazing how much easier it is to form. It will save you time, money, and weight.


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## Hannibal Lector (Oct 10, 2006)

> _Originally posted by OUTHOPU_@Jan 10 2011, 05:30 PM~19558869
> *Use 3/16" instead of 1/4". It's plenty strong enough and it's amazing how much easier it is to form. It will save you time, money, and weight.
> *


True. Bout the 3/16. But yeah if its 2-3hours a day. You'll be lookin around 2 months and if its a full wrap.


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