Skid plates & armor: When to use steel and when to use aluminum?

L0jik

L0jik

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While window shopping Genright and UCF; I see that they offer steel and aluminum versions for most of their body armor and skid plates. Now of course the idea of aluminum everything is nice because of the massive weight savings which are crucial, but of course sometimes the added strength is necessary.

So, in your opinons, what items should be steel, and what can be protected with aluminum at ~1/2 the strength?
Keep in mind there are:

Steering box skids
Oil pan/ Tranny skids
Transfercase skids
Gastank skids
Diff skids (Never really thought these were necessary)
Rocksliders
Bumpers
Fenders (I'm referring to full metal ones like Genright or Poison Spyder offers)
 
On mine I went this way


Steering box skids Steel Skidrow

Oil pan/ Tranny skids Alum Savvy

Transfercase skids Stock

Gastank skids Alum Savvy

Diff skids (Never really thought these were necessary) Running HD Diff Covers from Riddler

Rocksliders Steel Poison Spyder

Bumpers Front Steel Betstop, just replaced rear from Rock Hard 4x4 steel to Savvy Alum

Fenders (I'm referring to full metal ones like Genright or Poison Spyder offers) Originally ordered steel front fenders from Genright, But when they came in the weighted a TON so they went back and reordered them in Alum, also have rear corners in Alum.

After removing my HEAVY rear bumper and rack my jeep sit's level now, All this armor adds up to a lot
 
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What matters more than the basic material is the grade of material and how it is heat treated. You can buy some really crappy steel that will look and feel impressive, but bend if sneezed on. I'm sure we've all had an experience with a cheap imported tool... You can also get very high grades of aluminum. 7075 is one example, although it is rarely used in Jeep parts because it is very difficult to weld. 6061-T6 or T651 is far more common in skid plates.

Heat treating is also why you rarely see aluminum powdercoating for Jeep parts. Powdercoating steel using standard processes generally does not affect heat treatment. But a normal high temperature powdercoat will significantly change the properties of aluminum. There are low temperature powdercoating options sometimes used for aluminum.

In addition, manufacturers often offer aluminum in thicker plates. UCF, for example, offers steel in 3/16" and 1/4" and aluminum in 1/4" and 3/8". The thicker cross sections of the aluminum plates more than make up for the differences in material strength.

Aluminum does not rust, but it does corrode in salty and wet environments. It generally does so at a significantly slower rate than steel, but is often more difficult to detect and repair.

Personally, I would go with the thickest (or best reinforced) aluminum option.

I do have a steel gas tank skid, but it was the only one available when I bought by 24 gallon tank. I also removed the hitch receiver, which means that a low riding car could potentially strike the skid/tank if they rear end me and go under my bumper. So the steel remains. I plan to reinforce the area, and possibly even install a different hitch receiver to reduce the odds of puncturing the gas tank in a rear end collision.
 
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Plenty of bull about aluminum and steel floating around. For example aluminum control arms weigh more than steel. It definitely isn't just black and white like some people make it out to be. A cheap steel part is more likely to work fine, aluminum parts need to be well designed or they will be much weaker than their cheap steel counterparts
 
on my 4cyl YJ I have steel genright rockers, but went with an aluminum front bumper and ucf skids for the engine and trans/tc to save some weight..I would have done the same thing for the Metalcloak fenders/flares, but they weren't available back when I ordered mine...might swap some steel fenders out for aluminum ones down the road on this rig

for the 6cyl TJ, another aluminum ucf engine/trans/tc skid, but otherwise went with steel.. a Rockhard bumper and steering box skid, Metalcloak full corner guards, fenders/flares and rockers, but this time it's more of a build budget thing
 
Wouldn't a heavy steel transfer case skid plate be desirable over lightweight aluminum?

Considering its placement an extra 50lbs or so centered low on the frame would help to balance out the overall weight distribution of the vehicle. Steel resists abrasion much better as well.

I also fail to understand the purpose of savvy and ucf front aluminum bumpers. They seem so tiny that weight savings over steel is not that much. Then if you want bar work, you have to bolt it on. Then theres the hardcore upgrade from savvy, which is steel plates, skid plates essentially, that cover the aluminum bumper to give abrasion resistance.

Huh?

Why not just make it out of steel?
 
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you sure those Savvy corners aren't thick aluminum.........steel would not need to be that thick.
i made mine from 7ga steel backer and a 3/8" UHMW overlay that can be replaced should it get gouged up.

so tiny a weight savings???? my front bumper went from 50# of steel to 20# of aluminum. that tiny weight savings is over 50% for me.

the properties of the 60 series aluminum makes them tough as hell and not easy to bend.

like jjvw stated, not a bad choice for anywhere, but the rockers that spans long and 3/16-1/4" of steel is less profile and easier to form than the 1/4-3/8" 60 series aluminum it would take to be =. and the softer aluminum would gouge much easier in this location.
 
Feralkid said:
Wouldn't a heavy steel transfer case skid plate be desirable over lightweight aluminum?

Considering its placement an extra 50lbs or so centered low on the frame would help to balance out the overall weight distribution of the vehicle. Steel resists abrasion much better as well.

I also fail to understand the purpose of savvy and ucf front aluminum bumpers. They seem so tiny that weight savings over steel is not that much. Then if you want bar work, you have to bolt it on. Then theres the hardcore upgrade from savvy, which is steel plates, skid plates essentially, that cover the aluminum bumper to give abrasion resistance.

Huh?

Why not just make it out of steel?
Click to expand...

You're not seeing a lot of aluminum armor and lightweight builds out in the wild, are you?
 
Feralkid said:
Wouldn't a heavy steel transfer case skid plate be desirable over lightweight aluminum?

Considering its placement an extra 50lbs or so centered low on the frame would help to balance out the overall weight distribution of the vehicle. Steel resists abrasion much better as well.
Click to expand...
No, extra weight is extra weight and that is not a good thing ever.
Steel does not resist abrasion better when the correct aluminum is used.

I also fail to understand the purpose of savvy and ucf front aluminum bumpers. They seem so tiny that weight savings over steel is not that much.
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Having a rough night? Think about what you just said. The Savvy front bumper weighs 13 lbs. which is the same weight as the stock front bumper.

Then if you want bar work, you have to bolt it on. Then theres the hardcore upgrade from savvy, which is steel plates, skid plates essentially, that cover the aluminum bumper to give abrasion resistance.

Huh?

Why not just make it out of steel?
Click to expand...
The Savvy corners for the bumper are 3/8" 6061 T-6 and are there because the corners are welded and that makes them weaker when you tag the corner in the rocks.
 
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Feralkid said:
Wouldn't a heavy steel transfer case skid plate be desirable over lightweight aluminum?

Considering its placement an extra 50lbs or so centered low on the frame would help to balance out the overall weight distribution of the vehicle. Steel resists abrasion much better as well.

I also fail to understand the purpose of savvy and ucf front aluminum bumpers. They seem so tiny that weight savings over steel is not that much. Then if you want bar work, you have to bolt it on. Then theres the hardcore upgrade from savvy, which is steel plates, skid plates essentially, that cover the aluminum bumper to give abrasion resistance.

Huh?

Why not just make it out of steel?
Click to expand...

Most people fail to realize the overall importance of keeping weight down. Several years ago I went on a quest to lighten my Jeep. Through a combination replaced parts and useless items removed, I shaved around 500 lbs off my LJ. The results were crystal clear. Acceleration, handling, breaking and offroad climbing improved noticeably. I know this for sure, because I had a solid baseline to test from. That is, I wheel, largely, in the same park, taking the same obstacles repeatedly. One steep stairstep climb in particular always gave me problems. Sometimes I would make it up, after repeated attempts, and sometimes I'd have to back off.

After the diet, in similar wet conditions, I was able to climb the exact same obstacle, along with others, almost effortlessly. I noticed no ill effects whatsoever of removing full steel belly skids and replacing them with aluminum. Point being, there's already plenty of weight down low. The only caveat to this might be if you wheeled with top heavy loaded Jeeps, but that's a different problem.

Bottom line, every bit of weight saved truly matters in the big picture. Once you make the jump to aluminum you won't go back. I was so pleased with the results I even replaced my steel car trailer with an aluminum one.
 
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What takes an impact better? Aluminum or steel

Ok, so less weight is always better. Got it.

I've been looking at the genright front bumpers, this one caught my eye.

https://genright.com/products/tj-lj-trail-grill-guard-front-bumper-aluminum.html
They list a steel version as well.

They dont list the weights of their products though.

Would aluminum bar work protect the radiator in a collision with a tree branch or a deer?

I think it would crumple.
 
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Feralkid said:
What takes an impact better? Aluminum or steel
Click to expand...
That is one area that really confuses folks. Aluminum actually fares better in the armor grades. The reason is the yield strength and ultimate tensile strength of aluminum are very close together. With typical steel grades used for armor, they are much farther apart so while the steel will resist breakage at a higher level, it will yield much easier which translates to denting easier.

Another confusing area is weight versus strength. 6061 T6 is about 2/3's as "strong" as steel in similar armor grades but it weighs 1/3 as much. Put another way, 3/8" thick AL is the same weight as 1/8" steel. Would you rather have 1/8" steel or 3/8" aluminum protecting stuff if you were to go by protection per pound?
 
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Irun said:
Most people fail to realize the overall importance of keeping weight down. Several years ago I went on a quest to lighten my Jeep. Through a combination replaced parts and useless items removed, I shaved around 500 lbs off my LJ. The results were crystal clear. Acceleration, handling, breaking and offroad climbing improved noticeably. I know this for sure, because I had a solid baseline to test from. That is, I wheel, largely, in the same park, taking the same obstacles repeatedly. One steep stairstep climb in particular always gave me problems. Sometimes I would make it up, after repeated attempts, and sometimes I'd have to back off.

After the diet, in similar wet conditions, I was able to climb the exact same obstacle, along with others, almost effortlessly. I noticed no ill effects whatsoever of removing full steel belly skids and replacing them with aluminum. Point being, there's already plenty of weight down low. The only caveat to this might be if you wheeled with top heavy loaded Jeeps, but that's a different problem.

Bottom line, every bit of weight saved truly matters in the big picture. Once you make the jump to aluminum you won't go back. I was so pleased with the results I even replaced my steel car trailer with an aluminum one.
Click to expand...
Boiled frog syndrome. Folks add weight incrementally bit by bit and each one is hardly noticeable to the overall deterioration of performance until one day they have this lumbering pig of a rig that waddles up the trail.

The ones who really notice it are those who do a tear down to rework everything and take it for a test drive when everything is removed. Then they perk up and start listening when the detrimental effects of weight is being discussed.
 
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Feralkid said:
I also fail to understand the purpose of savvy and ucf front aluminum bumpers. They seem so tiny that weight savings over steel is not that much.
Click to expand...

Having owned both, the Savvy bumper is not just a little lighter than a steel bumper of a similar size, it's dramatically lighter. I was able to lift the Savvy bumper with ease using a single finger. That's not even remotely possible with a steel bumper.

The weight savings are no joke, they are indeed dramatic.
 
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Feralkid said:
What takes an impact better? Aluminum or steel

Ok, so less weight is always better. Got it.

I've been looking at the genright front bumpers, this one caught my eye.

https://genright.com/products/tj-lj-trail-grill-guard-front-bumper-aluminum.html
They list a steel version as well.

They dont list the weights of their products though.

Would aluminum bar work protect the radiator in a collision with a tree branch or a deer?

I think it would crumple.
Click to expand...
Again, it is vastly important to know which aluminum is being used. GR uses 5052 for that front bumper which is not a suitable grade for something used in the rocks. A buddy installed one, we told him not to, one trip to JV practically destroyed it.
 
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these are the 3/8" 6061 aluminum blanks i made for corner protectors on a bumper;).

notice no distortion at all from bending b4 it snapped, and believe me it was a loud pop under several tons of force and the wrong bending blade.
i've since made a nice fat round blade but need a press of about 20t to do it. and still do not know if i can make it work.

there is an art to bending 6061 aluminum. unless you know what your doing it's SNAP, CRACK or POP just like the cereal.

91271492_2834814076625911_7265109082955055104_n.jpg


91218412_237394900776221_2505710025297625088_n.jpg


and this is compounded by not having enough starting material and working against the grain as well.

edit for misspeaking: i bent it with the grain instead of against it, worded bassakwards. TY for correction.
 
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