Skid plate material - 5052 vs 6061

5052 or 6061?
I used the latter on my skid plate.
Noticed a local guy that makes Subaru ones is using 5052. Was wondering if there is much difference or benefit to one over the other. Quick internet search makes it look like 5052 is easier to bend but 6061 is stronger if it's being welded?

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Grant Hughes

Easier to bend when forming means easier to bend when whackin into junk-n-stuffs. Didya stink a dat?

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John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

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CALL +1 206 431-9696
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Who cares about welding? BMW skid plate doesn't need any bends just a couple creative tricks in mounting. Plate itself just needs 5 minutes of love with a grinder, or 1 minute with a plasma. I even know where there's a template.

Dave

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DaveK
Who cares about welding? BMW skid plate doesn't need any bends just a couple creative tricks in mounting. Plate itself just needs 5 minutes of love with a grinder, or 1 minute with a plasma. I even know where there's a template.

Dave

Everything needs some up-kick in the front---you ever watched somebody DNF cause the shitty designed sumpguard had an exposed leading edge and when they braked and hit some bumpelies the leading edge was transmogrified into a downward sloping shovel---which caught the dirt, was peeled back and they high centered the car ON THE BENT TO SHIT sumpguard?

I's seen it a couple of times.

leading edge UP and nestled on top of a L angle going across the front.

SAFER-er.

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John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
Remember! Pacific Standard Time
is 3 hours behind Eastern Standard Time.

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john vanlandingham
Everything needs some up-kick in the front---you ever watched somebody DNF cause the shitty designed sumpguard had an exposed leading edge and when they braked and hit some bumpelies the leading edge was transmogrified into a downward sloping shovel---which caught the dirt, was peeled back and they high centered the car ON THE BENT TO SHIT sumpguard?

I's seen it a couple of times.

leading edge UP and nestled on top of a L angle going across the front.

SAFER-er.

Mine still has 'kick' because of how it mounts (low point under front crossmember, front mount up higher at 5 degree slope or so. Besides, in a RWD car if you high center the car on an accordion'd skit plate, you can still steer it with the throttle.

Dave

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DaveK

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john vanlandingham
Everything needs some up-kick in the front---you ever watched somebody DNF cause the shitty designed sumpguard had an exposed leading edge and when they braked and hit some bumpelies the leading edge was transmogrified into a downward sloping shovel---which caught the dirt, was peeled back and they high centered the car ON THE BENT TO SHIT sumpguard?

I's seen it a couple of times.

leading edge UP and nestled on top of a L angle going across the front.

SAFER-er.

Mine still has 'kick' because of how it mounts (low point under front crossmember, front mount up higher at 5 degree slope or so. Besides, in a RWD car if you high center the car on an accordion'd skit plate, you can still steer it with the throttle.

Dave

That's because you drive a nice car from an earlier age and the ones i was talking about were those "below-a-rodent" things with all the crutches for folks that can't be bothered to learn to look for grip. So when they ran over ith with front wheels, they lost steering..
I wasn't laughing at the time, too much empathy... They chose the car but it was still a fellow competitor---even if the karma-fu was strong...(The one person had actually lodgeda formal protest about the illegal car for some dumb low placing, the car "had the wrong year plastic consol around the shifter"---Peee Gee Tea )

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John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
Remember! Pacific Standard Time
is 3 hours behind Eastern Standard Time.

http://www.rallyanarchy.com/phorum/read.php?5,22711

I was just looking into this and remembered this thread from a few years ago.

Modulus of elasticity:
5052-H36 70.3 GPa / 10200 ksi
6061-t6 68.9 GPa / 10000 ksi

Tensile Yield Strength:
5052-H36 241Mpa / 35ksi
6061-t6 310Mpa /45ksi

Source: matweb

The higher modulus of 5052 will mean that it's stiffer for the same dimension. The higher yield strength of 6061 means that it will take more force before it permamnetly deflects.
Both are weldable, but 6061 needs some time before it gains most of the t6 preperties back. Good bet is 30 days from welding it will have the majority of the t6 properties back.
5052 welds easier and has less problems with post weld cracking and fatigue.

My advice: Choose whatever you can find cheaper

Yeah I thought once you add heat to 6061 it loses the "6061" property and moves more towards a 5052/5058 type. I'm running from my fuzzy memory banks, but isn't 6061 just a heat treated version of a 5k series aluminum, so welding pretty much weakens the 6061?

I'd almost think if you welded 6061 you'd have to heat treat the skid plate over again to get uniform 6061 properties back in it?

Again, someone correct me where I am wrong. I'm going back on materials classes I took almost a decade ago.



Edited 1 time(s). Last edit at 05/16/2013 11:32AM by BillyElliot.

Solution heat treatment of aluminum is a little tricky. With 6061 when it is welded it goes back to the T0 treatment, aka- butter. If placed in an oven at 350°F for 3 hrs it will bring it back up. It can also age harden near enough back to T6 specifications.

5XXX and 6XXX are not the same alloy. If you look at the base elements they are very different. Copper is used as one of the main alloying elements (large amounts in 2XXX). Interstitials for the win!

An interesting value to look at would be the T0 state. This will be the softest and weakest case. So you can plan around that scenario as the worse case. Also, you are only loosing strength in the weld area. If these are over-built, then it really doesn't matter. You really want strength and stiffness in the rest of the big-ol-flat plate where it's going to see rocks and large impact loads.

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BillyElliot
Yeah I thought once you add heat to 6061 it loses the "6061" property and moves more towards a 5052/5058 type. I'm running from my fuzzy memory banks, but isn't 6061 just a heat treated version of a 5k series aluminum, so welding pretty much weakens the 6061?

I'd almost think if you welded 6061 you'd have to heat treat the skid plate over again to get uniform 6061 properties back in it?

Again, someone correct me where I am wrong. I'm going back on materials classes I took almost a decade ago.

Billy, the "6061" refers to the mixed alloy not the temper. The T-0, T-4, T6 are the different heat treats for this alloy. Also the Elasticity modulus remains with temper what increases is the yield and tensile strength.

Also 5052 has -0, H32, H34, H36 and H38 all different from one another with the later being the strongest, with very close yield and tensile strength to the 6061-T6.

So in the end its a toss up on which one is better, if the plate is relatively flat with just one bend then a 6061 would be good, if its going to be welded in various places then 5052 would be better because it tends to retain the modulus with temperature.

Like Robert said, get the cheapest. End of story.

I dunno about all this talk of welding on a skidplate. I've never found it necessary to weld anything on a skidplate. I always use 1/4" 6061 T-6. It can be bent successfully with the proper equipment if you don't make too sharp of a bend.. All you need is a little kick up in the front. This is how I usually do them:


Simple.

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Doivi Clarkinen
I dunno about all this talk of welding on a skidplate.

Not all cars are created equal.

Here's one from Subaru S12 World Car

Ruffles have ridges!!!

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Owner, Driver, Head Mechanic, and Janitor at Tower City Race Team, headquartered near L'Anse. Michigan.
Driver / CoDriver in Rally America, NASARallySport, ARA, AMS, UPMDA, Champ Off Road

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Cosworth

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Doivi Clarkinen
I dunno about all this talk of welding on a skidplate.

Not all cars are created equal.

Here's one from Subaru S12 World Car

Yes, and I bet that is a whole lot lighter and a whole lot more expensive then the one pictured above. But club level guys have to make their skidplate and their car last for a whole lot more than one or two events so compromises are acceptable. Different horses for different courses as they say.