QUESTION: Aluminum vs. Steel: aluminum or steel in car bodies?

[Hooke Road®]

Why is aluminum gaining popularity?
Aluminium has great advantages, both in terms of corrosion resistance and weight.
However, a critical question remains: aluminum comes at a higher cost compared to steel.

Both fender liners are suitable for the Jeep Wrangler manufactured by Hooke Road.
However, the right-side fender liner is an aluminum product designed based on the left-side steel fender liner.
In the future, we will also produce more aluminum products for different vehicle models.
So, what are your thoughts on these two different materials?

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[HighVelocity]

If it's good enough to hold my beer, it's good enough to hold me.

Besides, nobody cares about the Wrangler.

 

[Hooke Road®]

If it's good enough to hold my beer, it's good enough to hold me.

Besides, nobody cares about the Wrangler.

Yes, but we care about your ideas.
So maybe we'll hear more from you before we develop more products for bronco!

 

[Sir915]

Aluminum is great for most applications but I'd stick with steel for skid plates.

 

[Doc TOC]

What is the point here? Why?
Are owners saying they need it for their desert racing?

You can do fender liners in plastics or resins that are as effective as aluminum and cost way less..

And aluminum really is not a repairable material. Aluminum scratches, gouges, cracks, and deforms much easier than steel of comparable strength rating. Once it's messed up, you will be buying another (expensive) replacement. That doesn't seem conducive to off-road components.

 

[DewarT]

No need to bash a vendor who is looking for constructive input...

Aluminum is lighter... that is probably the only perceived benefit in my mind.

Steel and aluminum can both be coated or painted with similar success and both will protect parts of the vehicle you are trying to protect. Aluminum deflects more, but some aluminums will have a higher ability to 'bounce back' under lesser bending loads. Cost difference should be minimal if you have the ability to weld both..

Over time- Aluminum will corrode and steel will rust- even if painted/coated correctly.

On my rock crawler, I use all steel skid plates because I will beat it on the rocks. On my 6G Daily- I would probably do aluminum if the price point were similar. I'm sure a higher percentage of vehicles here are going for the 'look' with many also used for light offroading and overlanding, but still also a daily. This would be where lighter but functional protection and looks would win the day.

 

[zuke]

The choice of materials for fasteners is a big factor as well, Frequently with things like Fender Liners a vendor, or the end installer, will choose to use stainless steel fasteners, which is fine with a mild steel liner, but not so good with aluminum.

Compound that with the fact that using many smaller fasteners leads to a greater chance of breaking the powder coat or paint, and the risk for corrosion increases, also, many cheaper fasteners are not made with good quality stainless, and can rust themselves.

I'll choose a quality aluminum product with well thought out mounting and fasteners for most applications where I don't expect them to take a lot of direct abuse, like fender liners, Molle accessory panels, racks, etc.

If it's something I know is going to take a hit once in a while, Like a skid plate, rock rail, bumper, corner armor.. I'm gonna choose steel, I know I'll be replacing it on occasion, so cost is more of a factor.

 

[65CarryAll]

Rust/corrosion is the deciding factor. Steel bodied vehicles rust away, sometimes in short order. Sure, aluminum can corrode, but nowhere near to the extent of steel. Ford F-150's have been aluminum for 10 years now and are still holding up great. And they will continue to do so. Since I keep my vehicles a long time (and tired of watching them rust away) this is most important to me. Thank you, Ford.

 

[BigRed]

Rust/corrosion is the deciding factor. Steel bodied vehicles rust away, sometimes in short order. Sure, aluminum can corrode, but nowhere near to the extent of steel. Ford F-150's have been aluminum for 10 years now and are still holding up great. And they will continue to do so. Since I keep my vehicles a long time (and tired of watching them rust away) this is most important to me. Thank you, Ford.

X2!

 

[Doc TOC]

Rust/corrosion is the deciding factor...this is most important to me.

I love the '65 Carry All. Cool then. Still cool now.

But I don't agree on the corrosion point (although I acknowledge that corrosion protection is important to you). There are way less expensive alternatives to managing corrosion exposure than using aluminum. With today's advanced coatings, you don't need to add a high cost material to manage corrosion. Good cleaning and maintenance routines will keep your car rust free for as long as you want. On the other hand, if your work truck is a beater, then what did you expect?

No need to bash a vendor ...

Bashing?!? You're way to sensitive.
OP asked an open ended question with a vague reference. And really a technical engineering question at that. Forcing the reader to guess what you are actually talking about is not good marketing. Pointing out they failed to provide adequate information is not bashing. If I schooled OP about 6th grade English, that would be bashing.

Steel and aluminum can both be coated or painted with similar success

Half true. Aluminum's oxidation coat requires different (more expensive) cleaners and primers than steel. Different chemistry.

Aluminum deflects more

Not true. It is the reverse. Steel has a higher module of elasticity (200 GPa) than aluminum (70 Gpa). Aluminum has the higher plasticity (deformation) than steel.

Cost difference should be minimal if you have the ability to weld both.

Not true. The cost to weld aluminum is significantly more expensive than steel and requires more environmental control ($$) for a clean weld. The HAZ effect on aluminum alloy tempers is more dramatic and can create a failure point or zone.

Over time- Aluminum will corrode and steel will rust- even if painted/coated correctly.

Not true. Raw aluminum oxidizes in nanoseconds with the oxygen in air. Once all the AL atoms have bonded with oxygen, a non-permeable, white crystal layer is formed coating the piece and oxidation stops, protecting the underlying AL lattice. Adding a coating (annodizing/powder coat/paint/etc.) further stabilizes and isolates the layer. Until the crystal structure is disrupted chemically or physically, no further oxidation (aka corrosion) occurs.

Iron corrosion will continue as long as water vapor and oxygen are present. The oxidized layer is permeable and allows water and oxygen to reach deeper iron atoms in the lattice. Adding a non-permeable coating isolates the the iron, until it is disrupted chemically or physically.

So, if you're cleaning and maintaining the protective layers, there will not be any further corrosion. Abuse it and loose it

 

[KyTruckPlant]

I love the '65 Carry All. Cool then. Still cool now.

But I don't agree on the corrosion point (although I acknowledge that corrosion protection is important to you). There are way less expensive alternatives to managing corrosion exposure than using aluminum. With today's advanced coatings, you don't need to add a high cost material to manage corrosion. Good cleaning and maintenance routines will keep your car rust free for as long as you want. On the other hand, if your work truck is a beater, then what did you expect?



Bashing?!? You're way to sensitive.
OP asked an open ended question with a vague reference. And really a technical engineering question at that. Forcing the reader to guess what you are actually talking about is not good marketing. Pointing out they failed to provide adequate information is not bashing. If I schooled OP about 6th grade English, that would be bashing.


Half true. Aluminum's oxidation coat requires different (more expensive) cleaners and primers than steel. Different chemistry.


Not true. It is the reverse. Steel has a higher module of elasticity (200 GPa) than aluminum (70 Gpa). Aluminum has the higher plasticity (deformation) than steel.


Not true. The cost to weld aluminum is significantly more expensive than steel and requires more environmental control ($$) for a clean weld. The HAZ effect on aluminum alloy tempers is more dramatic and can create a failure point or zone.


Not true. Raw aluminum oxidizes in nanoseconds with the oxygen in air. Once all the AL atoms have bonded with oxygen, a non-permeable, white crystal layer is formed coating the piece and oxidation stops, protecting the underlying AL lattice. Adding a coating (annodizing/powder coat/paint/etc.) further stabilizes and isolates the layer. Until the crystal structure is disrupted chemically or physically, no further oxidation (aka corrosion) occurs.

Iron corrosion will continue as long as water vapor and oxygen are present. The oxidized layer is permeable and allows water and oxygen to reach deeper iron atoms in the lattice. Adding a non-permeable coating isolates the the iron, until it is disrupted chemically or physically.

So, if you're cleaning and maintaining the protective layers, there will not be any further corrosion. Abuse it and loose it

I assume then, that somewhere in all of that explains why we have a window of time that we can stamp AL body parts, construct the body, and get it through E-Coat?

 

[flip]

501-26 Body Repairs - Vehicle Specific Information and Tolerance Checks	2022 - 2023 Bronco​
Description and Operation	Procedure revision date: 04/30/2021​

Vehicle Specific Body Construction
For recommended metal repair guidelines and recommendations, refer to the following illustrations and:
For additional information, refer to: Specifications (501-25 Body Repairs - General Information, Specifications).
.

Bumper Beams

Bumper beams are typically constructed of high-strength (HS) or stronger class steel. If the bumper beam shows evidence of a kink or tear it is not repairable and must be replaced. The use of heat to repair these components is not allowed and will result in weakening the component. Minor damage made be corrected through cold straightening only.

Steel Type Legend

Item	Steel Type	Color
1	Mild Steel	Yellow
2	Bake Hardened Steel (BH)	Light Blue
3	Solid Solution Strength	Pink
4	High Strength Low Alloy (HSLA)	Dark Blue
5	Dual Phase (DP) 500, 600 Class Steel	Green
6	Dual Phase (DP) 700, 800, 900, 1000 Class Steel	Fuchsia
7	Laminate Steel	Teal
8	Ultra High Strength Steel (UHSS) Martensitic, Boron	Red
9	Transformation Induced Plasticity Steel (TRIP)	Gold
10	Aluminum/Magnesium	Purple

Front Floor

Item	Description	Steel Type
1	Tunnel reinforcement	Dual phase (DP) 800 steel
2	Crossmember assembly	Dual phase (DP) 600 steel
3	Crossmember assembly	High-strength low allow steel (HSLA)
4	Bracket support	High-strength low allow steel (HSLA)
5	Crossmember assembly	High-strength low allow steel (HSLA)
6	Lower side member	Dual phase (DP) 800 steel
7	Side member floor	High-strength low allow steel (HSLA)
8	Floor pan assembly	Mild steel
9	Bracket support	Dual phase (DP) 800 steel
10	Lower side member extenstion	Dual phase (DP) 800 steel
11	Side member floor	High-strength low allow steel (HSLA)

Rear Floor 3 Door

Item	Description	Steel Type
1	Rear floor pan extension	Mild steel
2	Rear floor pan	Bake hardened (BH) steel
3	Back panel assembly	High-strength low allow steel (HSLA)
4	Cross member	High-strength low allow steel (HSLA)
5	Rear side member	High-strength low allow steel (HSLA)
6	Center floor pan assembly	Mild steel

Rear Floor 5 Door

Item	Description	Steel Type
1	Rear floor pan extension	Mild steel
2	Back panel assembly	High-strength low allow steel (HSLA)
3	Rear side member	High-strength low allow steel (HSLA)
4	Center floor pan assembly	Mild steel
5	Rear floor pan	Bake hardened (BH) steel

Cowl Panel and Dash Panel

Item	Description	Steel Type
1	Upper cowl panel	Mild steel
2	Cowl panel assembly	Mild steel
3	Dash panel assembly	Mild steel

Roof

Item	Description	Steel Type
1	Rear roof reinforcement	Bake hardened (BH) steel
2	Roof bow	High-strength low allow steel (HSLA)
3	Roof bow	High-strength low allow steel (HSLA)
4	Front roof reinforcement	Bake hardened (BH) steel

Body Side Panels 3 Door

Item	Description	Steel Type
1	Reinforcement	High-strength low allow steel (HSLA)
2	Roof side reinforcement	High-strength low allow steel (HSLA)
3	Upper quarter reinforcement	Solid solution strength steel
4	Drain trough	High-strength low allow steel (HSLA)
5	Quarter panel	Bake hardened (BH) steel
6	Body side panel	Bake hardened (BH) steel
7	A-pillar	Boron steel
8	Rocker panel reinforcement	Boron steel
9	A-pillar upper reinforcement	Boron steel
10	A-pillar upper outer panel	Mild steel
11	Roof side rail reinforcement	Boron steel
12	Roof side rail reinforcement	Boron steel
13	Roof side reinforcement	Boron steel
14	B-pillar inner	Boron steel

Body Side Panels 5 Door

Item	Description	Steel Type
1	Quarter panel	Bake hardened (BH) steel
2	Body side panel	Bake hardened (BH) steel
3	B-pillar	Boron steel
4	Rocker panel reinforcement	Boron steel
5	A-pillar	Boron steel
6	A-pillar upper reinforcement	Boron steel
7	A-pillar upper outer panel	Mild steel
8	Roof side rail reinforcement	Boron steel
9	Roof side rail reinforcement	Boron steel
10	Roof side reinforcement	Boron steel
11	Reinforcement	High-strength low allow steel (HSLA)
12	Roof side reinforcement	High-strength low allow steel (HSLA)
13	Inner quarter reinforcement	High-strength low allow steel (HSLA)
14	Drain trough	High-strength low allow steel (HSLA)
15	Inner quarter panel	Mild steel
16	Inner quarter reinforcement	Mild steel
17	Inner quarter extension	Dual phase (DP) 800 steel
18	Inner quarter upper reinforcement	High-strength low allow steel (HSLA)
19	B-pillar inner	Boron steel

Front Panels, Aprons and Side Members

Item	Description	Steel Type
1	Fender apron brace upper	High-strength low alloy (HSLA) 340 steel
2	Fender apron brace lower	High-strength low alloy (HSLA) 340 steel
3	Radiator support	High-strength low alloy (HSLA) 340 steel
4	Fender apron brace lower	High-strength low alloy (HSLA) 340 steel

Front Door

Item	Description	Steel Type
1	Door shell assembly	Aluminum
2	Door intrusion beam (part of door shell assembly)	Boron steel
3	Door outer panel	Aluminum

Rear Door

Item	Description	Steel Type
1	Door shell assembly	Aluminum
2	Door intrusion beam (part of door shell assembly)	Boron steel
3	Door outer panel	Aluminum

 

[5GENIDN]

I think both steel and aluminum have their pros an cons... For a fender liner.... I like my factory one piece. I do not like the idea of multiple pieces that have to be attached to each other. You are not going to get up in the fender and weld those together on a DIY. That is why they bolt together and that is exactly where they fail.... long before corrosion of any kind. Look at the complaints for any brand steel or aluminum.... The joints fail, they become loose, they rattle, then a tire catches an edge and tears them up.... Me, I like a one piece polymer fender liner.

 

[flip]

IIRC the 2015 F150 used a 7000 series aluminum and was virtually impossible to repair due to work hardening from dings/dents/hail/other impact. Ford forced us to buy a ton of body repair equipment to work on these including setting aside a space that was walled or curtained off to do the repairs. The idea was less chance of airborne ferrous dust falling on areas being sanded or worked with the special hammers and dollies. Can't remember the last time any of it was used since most of the repairs now are full panels already e-coated which are glued and use spr or regular rivets in specific spots for the mechanical bond. The less we expose bare alum the lower the chance of corrosion starting.

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