Material thickness for bumper fab

[Wile E Coyote]

I asked a very similar question before, yet can't find my post, nor remember details.

Looking to finally get around to replacing the stock front bumper I cut off 2 yrs ago, and would like to use 6x2x1/8" rect. tube for the main bumper. Winch plate will be separate, and all of it tied to the frame rails via 1" plate. 90% + copy of 2MBB's very well liked design. It will see rocks, a hi-lift, etc, but this is a family wheeler that DD's.

Am I asking too much of 1/8" mild steel in the name of weight savings?
Aren't ARB's 10 ga? With 1/8" at 11ga, I'm not far off, IMHO. I do understand that an engineered bumper (ARB) should handle loads diff than a basic rectangle.

 

[Dynosoar]

I would not go under 3/16ths. I like bumpers to be over built so even 1/4 would not be out of the question.

Dynosoar

 

[cruiser88]

I would go with a combination of 1/8 and 1/4

 

[Cruisified]

I'd rather my bumper bend or crack than my frame. 1/8" is perfect you can hi-lift off it, it'll take abuse but not overload the front end. Plus half the fun is re-building them anyways.

 

[ntsqd]

You gain considerable rigidity by using the box tubing over the open rear of designs like the ARB. The 10ga bodied front bumper (ARB-like design) on my Mini took a direct hit from a wanna-ba Class 5 Open Baja (nearly full tube framed) in an offset head-on (left headlights just about perfectly aligned). He managed to bend the bumper, but not by a lot. I have no worries about using 1/8" in an appropriate design.

That said, I'd like to see more depth than just 2" in the design.
Where rock rash is likely or a concern I would suggest laminating some additional thickness there. Carry the weight only where you need it.

 

[Wile E Coyote]

Thanks for the advice thus far.
I'm not sure it's appropriate to build a bumper a whole lot stronger than the frame it's tied in to. I like beefy as much as the next guy, I just don't want it hanging off the end of my truck. 1/8" main structure with 3/16" strips along the bottom edge is as much weight as I'd like to add. That along w/ a somewhat lightened winch would do my rig justice. Just don't wanna waste my energy building something that someone with experience can say amounts to glorified tinfoil.

 

[freds40]

1" frame tie-ins are way overkill. Really 1/2" is plenty for just 2 locations and you can get away with much less depending on the number of tie-in locations you have.

 

[cruiser88]

Thanks for the advice thus far.
I'm not sure it's appropriate to build a bumper a whole lot stronger than the frame it's tied in to. I like beefy as much as the next guy, I just don't want it hanging off the end of my truck. 1/8" main structure with 3/16" strips along the bottom edge is as much weight as I'd like to add. That along w/ a somewhat lightened winch would do my rig justice. Just don't wanna waste my energy building something that someone with experience can say amounts to glorified tinfoil.

Right on.....bumper needs to give a little. Let me know if you need pictures of a ARB to go by or something

 

[ntsqd]

1" frame tie-ins are way overkill. Really 1/2" is plenty for just 2 locations and you can get away with much less depending on the number of tie-in locations you have.

Second this. The thickest the mount plate needs to be is one mounting bolt diameter and it can be somewhat thinner without being an issue. Go too thin and you'll have troubles, so maybe use an ROT of between 1/4 of the bolt diameter and one bolt diameter for the mount thickness.

Consider the thickness that you are bolting it to.

If at all possible have bolts in more than one plane, say sides and top or sides and bottom. All three would likely cause fitment troubles.

 

[cody c]

i replaced my cracked front springs a couple years ago, i had a very solid bumper that weighed about 150lbs not including the winch. Hit a few holes hard with a heavy front end and youll see what i mean.
I would suggest keeping it tight to the vehicle, and sometimes less is more when it comes to how you build it.

 

[Wile E Coyote]

1" frame tie-ins are way overkill. Really 1/2" is plenty for just 2 locations and you can get away with much less depending on the number of tie-in locations you have.

I didn't specify enough, sorry. The frame tie-ins pierce the main bumper and double as tow points, as per a common design. Otherwise, the 4x12x1" plate would be stupid overkill, I agree.
Perhaps I can link my inspiration thread: https://forum.ih8mud.com/60-series-wagons/77311-front-bumper-project.html