Sheet metal vs. Body panel gauge???

Hi, I would like to know if there is a differents in body panel steel and mild steel?? If a car hood is 18ga and a peace of 18ga sheet metal is the same. Way will one have louver punch in it easyer than the other. Is car steel mild, cold rolled or hot roller. Can any one please HELP?? Thanks..

 

http://www.sheetmetalguy.com/sheet_metal_gauge_chart.htm

I've read Ford used 19 gauge, so you just use some mild steel 18 and go to town. Most seem to prefer cold rolled, I think there is more slag?crap on the surface of hot rolled.

 

Type of steel, not the thickness, is probably the main difference. I think they use a type that is easier to form for body parts.

 

Cold rolled sheet is what you want, 18, 19 or 20 gauge is best for bodypanels. Cold rolled is rolled and formed cold, hence the name, and it has tighter tolerances and a nicer slag free finish. Hot rolled is rolled while hot, and then ends up with slag on it. If you take a piece of cold rolled and hammer it over in the vice, and take a piece of hot rolled, you will see the crap pop off of the hot rolled.

Use cold rolled for sheetmetal, and you can take your pick on thicker stuff for brackets, frame parts, etc. There are several other options for the thicker material, such as P&O (pickled and oiled) which is basically hotrolled with some things done to it afterwards to improve its appearance.

To sum up for you, a car panel should react the same as cold rolled, unless you get a newer car that has some of the high strength steel in it, but I very well doubt you will, as that is also on in certain structural areas of the cars anyways, and it is new.

Probably more than you wanted to know. LOL

Brian =)

 

THANKS, guy. That's a lot of help..

 

I am a retired sheet metal worker and we used 21 gauge cold rolled metal made for forming body panels,much more plyable,on all our custom body panel products. ROY.

 

cold roll is stronger than hot roll when it comes to bending it

 

With out going to it cold rolled is more pliable as per specs.

 

If you are looking for good sheetmetal for forming body panels, 19 ga. AKDQ is the type favored by many pros. The AKDQ is short for "aluminum killed, draw quality". Yes, we're talking steel, not aluminum, that just refers to the mill process and the "draw quality" indicates it's greater stretchability for being drawn into or over dies without tearing. That is, of course, an equally a beneficial quality when hand forming panels.

Ray

 

Lots of good stuff. Thanks

 

Hi Guys,

Very helpful. I need to repair splotchy rust-through cancer on the LR door on my Cord. The door skin feels thin overall, so I think I a will be using 19 to 21 gauge cold rolled steel. Any other suggestions?

 

I'd bet the outer panels on your Cord are 18 or 19 ga. 21 ga. will test your welding skills more as well.

 

There are different grades of steel be it hot rolled or cold rolled. So how it punches depends on the grade or carbon content of the metal. Most of what you buy in the metal store is mild steel and will form and punch just fine. But you can buy higher carbon content if you like.

What you want for body panels or patch panels is going to be 18 gauge mild cold rolled steel in most instances. Some racers or people who are being weight conscious will opt 20 gauge and work with it to lighten things up. One should stay away from alloys if at all possible.

 

Thank you, gentlemen.

 

Be aware that there are many differences in both thickness and hardness in the cold rolled sheet available today. I have seen 18ga vary in thickness from .040 to .045, and the construction of the sheet can change alot depending if you get U.S. or Chinese product. There is also 19ga available, but harder to get and more expensive. Try and find a section of the vehicle you are working on that is still `as stamped` and measure its thickness. As an aside--I have just pancaked a `41 International Pickup (sectioned 2'' out of the roof crown above the doors, and chopped only the windshield 1 1/4'' ) and the steel used to stamp those pieces when new is among the best, most workable of all the old bodies I have come across......Get something as close to what you have as you can. Then try to do the best repair possible. Lapped welds, Mig tacks and Bondo in large quantities are not great examples of that, but everyone has to start somewhere.....

 

good info

 

I would think that back in the day it was just mild steel. Like everything else as technology progressed so did everything else. Today's cars use 22 gauge steel. Steel called boron and martensitic. Try drilling through that stuff!!!!. Cold rolled is definitely what you want for making panels