Steel or Aluminum Armor?

LOL nice data!

 

The new trd skid plate is 1/4” aluminum, which is what aftermarket skid makes use. I’d say it’s comparable in strength, and really not too much more price wise. I can understand the appeal.

That and a hitch. I sure wouldn’t want to be towing with an aluminum hitch.

 

I went with steel for all of my armor except mid and rear skids.
My front skid is Pelfreybilt. After Pelfrey shit the bed, I was too lazy to see if any other brands would mate up to it. The only mid and rear Pelfreybilt skids I could find were aluminum. If I ever need to replace skids, I’ll be going with BAMF.

 

For those who went with aluminum, did you get it powder coated or leave it bare?

 

I went bare.

 

The skid plates are bare. They just get nicked and scratched anyway.

Regarding the whole alum vs steel thing. Yes, steel is stronger. Yes, it bends and maybe can be repaired more easily if you're into that sort of thing. But honestly, an alum skid plate is a consumable item and if I break it, I'll just replace it.

 

You could probably go with bilstein 6112s and be out less money than buying used trd pro takeoffs. I have used bilsteins quite a bit on a few crawlers and they have worked great under a LOT of stress

 

Thats what I don't understand, a lot of guys put 33s on their truck and all of a sudden they say they get 12mpg. I have 35s and a steel front bumper getting 16-17 mpgs. I dont live in a big city either though so traffic is usually pretty good on the freeway.

 

Thats an expensive consumable item. I understand wanting to save weight, but for me steel skids make more sense.

 

Also taking a hard enough hit to break one could also take out an oil pan or something else you care about. Everyone has priorities though, and it's not my truck, so to each their own.

 

My two aluminum skids are cheaper than a new set of tires, AND I haven't actually had to change my armor yet, so... I guess it's all relative.

I kinda see the armor as an insurance policy, not as a permanent addition. Steel is rad though. I'm not against it. I do believe that if people aren't going balls-out hardcore rock crawling, then aluminum *might* be a fair trade-off.

 

Yeah, the logical conclusion of this argument is that no protection is good enough. And that's fair. You make the judgment to add the protection that you need.

 

Its better than nothing which I am currently running lol. Don't have the funds for skids yet. Aluminum is probably fine, I'd just feel better with steel.

 

I just dont trust aluminum. On my 4runner crawler I bought a brand spanking "new" rebuilt Marlin w56B HD transmission. When I went to install it, I dropped it about 4 feet and cracked the housing where it mates up to the dual transfer cases. I had to beg them for a blank housing shell, take apart the transmission, then install the new housing shell.


Thats a 4 foot drop on an aluminum housing onto concrete. Since then I dont trust aluminum for any kind of protection on my trucks. Steel is heavier, but does the job.


This pic was right before I noticed I put a 3 inch long hairline crack in it.

 

I have an aluminum IFS skid because I do very minimal offroading, and even then I'm not dropping it on rocks. Just not something I'm willing to do with a $25k daily driver. I did want at least some kind of protection for my oil pan though. Living in a rust belt state, it's also nice not needing to repaint every year.

 

(That isnt an issue with aluminum, that is an issue with castings)

I wouldn't recommend dropping cast aluminum or cast iron. Neither has enough elongation to talk about.

Wrought material or forgings for durability, not castings.

 

Interesting. That seems to indicate that the IFS plate I have on my truck, which is a 7 ga A36, shouldn't be able to hold up my truck when I use it as a jack point? If I'm reading right your hypothetical 1025 test plate would yield at 1,000 lbf and A36 won't be tremendously different. I'm obviously wrong in my rant then. I thought I was starting to get a handle on what you MEs talk about but I'm clearly not.

 

Calculations are for flat plate 24"x24" with no reinforcements and edge support. (I just made that up without regard to actuals). Does that describe your plate very well? My guess is that it doesnt. Mine has significant reinforcements.
(I was just at work and did those calcs for shits and grins just for comparison)

Note I didnt include effects of plastic bending, as all will see improvement from that...

 

No, obviously not. Just that I'd have thought in the hypothetical that it would have taken more than a 1/4" 6061 to achieve close to similar deflection and yield as 3/16" 1025, that's all.

This is what happens when you take an old engineer and try to learn him new things. Trying to understand material science, which is what I'm currently attempting to do for continuing education requirements.

 

Sorry for thread hijack...
It's because of the thickness term cubed in stiffness, even though the steel modulus is 3 times higher than aluminum.

Numbers FOR COMPARISON ONLY
3x(.190)^3=0.021
1x(.25)^3=0.016

So the 0.25" aluminum isnt quite as stiff as the 0.190" steel for flat plate bending, but it is close. At 0.28" it would catch up for stiffness.