When did body metal get thinner?

[Sam_Fear]

So in general, when did cars start getting made with thinner gauge steel?

What I'm really curious about is when they went to the real thin stuff like my '85 Cutlass was stamped from - that stuff is a PITA for me to weld. I'm guessing that happened late 70's?

I know my '59 F100 bed was a lot heavier than my '64 F100 bed - double wall construction. I assume trucks and vans stuck with the heavier gauges longer. Was there another thinning in the 60's? Was it all just a slow progression year over year?

 

[Tripper]

I think as gas prices went up all manufacturers looked to make their cars & trucks lighter! Hence the mini truck... I even had a '76 LUV truck. My oldest daughter on the left & her girlfriend at our place in the hills of Austin!

BoB

 

[Dr Crankenstein]

My 2 cents as I recall from tech school. (Almost 30 years ago. )

Early cars used heavier gauge because of the complex shapes. They needed soft material and enough of it to form complex shapes. (The trunk of your Olds, for example). When vehicles became more slab sided, they lightened up the gauge. Then came the "energy crisis" and the unitized body. Low carbon steel was replaced by HSS and the rest is history.

More info than anybody needs, but here's a link...

http://www.auto-maintenance-repair.com/r/High-strength-steel.html

 

[sgtpontiac]

I do believe you are correct Doc...

My 2 cents as I recall from tech school. (Almost 30 years ago. )

Early cars used heavier gauge because of the complex shapes. They needed soft material and enough of it to form complex shapes. (The trunk of your Olds, for example). When vehicles became more slab sided, they lightened up the gauge. Then came the "energy crisis" and the unitized body. Low carbon steel was replaced by HSS and the rest is history.

More info than anybody needs, but here's a link...

http://www.auto-maintenance-repair.com/r/High-strength-steel.html

Yeah, if you look at the changes in the body styles in the mid 70's you will see that they were more boxed and sharper edges with less rounded curves.....when they downsized all the GM cars in 77 seemed to mark the end of the heavy metal cars....plastic and lightweight metals became the answer to higher fuel economy.....

 

[Old Iron]

Yea I tend to agree, remember when the Chevy pickup doors would crack where you lay your arm with the window down and the hoods would bend in the middle if the hinges got the least bit dry from no oil.
GM started a campaign saying We're bending metal to make our vehicles stronger. Didn't say they were increasing the thickness just bending.

 

[Sam_Fear]

The reason I asked, I've got a stupid project cooking in my brain and I will eventually need curved panels to work with. I figure I might put an ad on CL, but I wanted to put a cut off date as to how new of stuff I can use.

Think I'll stop at 1970, or maybe 1975.

 

[klink]

22ga is common through pretty much all years. I'm not suggesting that everything uses this thickness, but all of the cars I've messed with to date have used this thickness.

Make a template of the general curve you need and go to a junk yard and I'm sure you'll come away with some pieces that will work.