This is why you need to understand material properties

So who made the bumper?
It doesn't matter who made it. What matters is that folks who are interested in aluminum understand what material to look for and why. If you see a bumper or armor with tight 90 degree bends like you see on this one, it is not material suitable for hard use.

This is not 6061 T6.
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If you try to do that with 6061 T6 it will just break at the bends.
 
Reason I asked is that not all companies list the material used and many people don’t know what to look for. Wasn’t looking to slam the maker (I in fact run a lot of their stuff on my Jeep), I was just curious, but I figured it out.
 
If I'm not mistaken, the damaged bumper in the first post is sold as being 6061-T6. The bends suggest otherwise.
 
6061 will bend, but it has to have a decent radius on the inside of the bend. I believe i was told 1/4" minimum inside radius for 1/8" thick 6061-T6. I always spec 5052 for bent parts because in my world bent parts are for enclosures. Parts that need strength are machined from 6061 or 7075.

I saw a couple pics of bumpers with nice bend radii that could be 6061 in a google search. The second one posted here is definitely not.
 
6061 will bend, but it has to have a decent radius on the inside of the bend. I believe i was told 1/4" minimum inside radius for 1/8" thick 6061-T6. I always spec 5052 for bent parts because in my world bent parts are for enclosures. Parts that need strength are machined from 6061 or 7075.

I saw a couple pics of bumpers with nice bend radii that could be 6061 in a google search. The second one posted here is definitely not.
That 1/4" bend radius sounds about right for 1/8". 3/16" used for the Savvy Fairlead mount on the bumper is 5/16" and the tonnage for the bend is silly. To do a 16" long bend takes real close to 30 tons to get it to 90 degrees.
 
This thread makes me think of the predicament it put Mr. Blaine in while making sure the rig was safe and ready.


In my remodeling company I avoid using clients toilets...doing a basement once I ran upstairs and took a whiz...then flushed the toilet ..someone had left it stopped up. Oh great . Flooded the room , it had wood floors.


Hope it all works out ok on that .
 
This thread makes me think of the predicament it put Mr. Blaine in while making sure the rig was safe and ready.


In my remodeling company I avoid using clients toilets...doing a basement once I ran upstairs and took a whiz...then flushed the toilet ..someone had left it stopped up. Oh great . Flooded the room , it had wood floors.


Hope it all works out ok on that .
The owner is a friend. He was warned before it was run in the rocks that it would fail miserably. He chose to ignore sound advice. His reaction to the warning was something along the lines of "how bad can it be?" Now he knows.

We've never dealt with a clogged toilet. We did have a mystery water leak from an upstairs master bath that we remodeled that was directly over a very fancy 1st floor entry way. They screwed down the subfloor. Drywall screw went 1/8" into one of the new copper lines. Took a bit for the point to rust off and let it start leaking. The fancy bead board wood paneling was ruined anyway so it was easy to repair from the bottom side. Not cheap, but easy.
 
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well you can always upgrade to 7075-T7451, it needs a big radius to bend and you will use hiloc's instead of welding but it will probably last longer than a frame...
 
well you can always upgrade to 7075-T7451, it needs a big radius to bend and you will use hiloc's instead of welding but it will probably last longer than a frame...
If you think folks will pay 2 grand for a front bumper, I'll get right on that.
 
That's starting to get annoying, and old, and busted, and unwarranted. (not sarcasm)
Apparently you just have no sense of humor today.

If i some how have offended you i apologize.

I fully understand the cost vs benefits and how the effect sales. Sometimes it just not worth using aluminum when it comes to design limitations and material selection. Personally i like steel in areas that are prone to impact.

This is heavily influenced by my location were rust it not an issue. I can see why people in high salt and rust prone areas would want aluminum. The biggest issue with aluminum is that when you weld it you change the heat treatment in the area of the welds. I am not aware of any grade of aluminum that eliminates this problem. I am not a welder but I do work with aluminum.

While i can not speak to every aircraft but 7075-T6 is the universal substitute for all material on my platform. It has great strength but it can not be welded. (According to the welders at work).

It would be interesting to see 7075-0 water formed than heat treated to T6. Im certain the cost would be outrageous. But i wonder if the strength would be improved by eliminating the welds.
 
Apparently you just have no sense of humor today.

If i some how have offended you i apologize.

I fully understand the cost vs benefits and how the effect sales. Sometimes it just not worth using aluminum when it comes to design limitations and material selection. Personally i like steel in areas that are prone to impact.

There are few applications on a TJ I can't design a normally steel part for in aluminum and have it be equal in performance.

This is heavily influenced by my location were rust it not an issue. I can see why people in high salt and rust prone areas would want aluminum. The biggest issue with aluminum is that when you weld it you change the heat treatment in the area of the welds. I am not aware of any grade of aluminum that eliminates this problem. I am not a welder but I do work with aluminum.

And, you design around that fact.

While i can not speak to every aircraft but 7075-T6 is the universal substitute for all material on my platform. It has great strength but it can not be welded. (According to the welders at work).

It would be interesting to see 7075-0 water formed than heat treated to T6. Im certain the cost would be outrageous. But i wonder if the strength would be improved by eliminating the welds.

About as interesting as making armor out of titanium. Sure, it is stronger in most respects but the benefit will not support the cost especially when we can do 98% of what we need to with 6061 T6.
 
About as interesting as making armor out of titanium. Sure, it is stronger in most respects but the benefit will not support the cost especially when we can do 98% of what we need to with 6061 T6.

I was more referring to high impact critical areas like front bumpers. Like the one you posted in the first post. I noticed the crack was right in the high heat area of the weld were the temper was chaged doe to welding. I have seen the same failure point in welded 6061.

By interesting i would like to see if 7075-T6 would have been as damaged as bad as the 505x. As far a i know no one it building bumpers from 7075. I do know that auto manufacturers are useing it in uni -bodys. I am not an engineer i don't have access to testing. That doesn't stop me from thinking about possible alternatives.

Finally. . . i agree cost is important and i doubt anyone would spend the money to test something like that when 6061 works just fine.
 
I was more referring to high impact critical areas like front bumpers. Like the one you posted in the first post. I noticed the crack was right in the high heat area of the weld were the temper was chaged doe to welding. I have seen the same failure point in welded 6061.

By interesting i would like to see if 7075-T6 would have been as damaged as bad as the 505x. As far a i know no one it building bumpers from 7075. I do know that auto manufacturers are useing it in uni -bodys. I am not an engineer i don't have access to testing. That doesn't stop me from thinking about possible alternatives.

Finally. . . i agree cost is important and i doubt anyone would spend the money to test something like that when 6061 works just fine.
The same failure point does exist in the Savvy bumper I designed which is why there are corner braces that bolt over the joint and stop the failures. Just a simple exercise in design and knowing how to work with the material.
 
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The same failure point does exist in the Savvy bumper I designed which is why there are corner braces that bolt over the joint and stop the failures. Just a simple exercise in design and knowing how to work with the material.
And that is why im not a designer of parts. I don't always see the simple solution to a complicated problem.

Thank god Boeing gives me pictures to build from.
 
And that is why im not a designer of parts. I don't always see the simple solution to a complicated problem.

Thank god Boeing gives me pictures to build from.
I'm not being entirely forthcoming. The reason I am so aware of the problem is due to how many steel bumpers we destroyed in JV.

This is a mild case of what happened.
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Note upward bend in lower edge which is why the Savvy bumper has a reinforcement that goes up and touches the round tube front crossmember.

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Same problem with rear bumpers.

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A twofer. Why poly body lift pucks suck and why we raise the OEM mounts on the side of the frame.

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That is the area I designed products for based on all the damage I've seen happen to steel parts.
 
It might help to not grind the welds, in the aviation world, you leave the welds visible because it is stronger. They are less likely to crack.