The Stovebolt Site Forums The Shop Area General Truck Talk Steel

Need to repair a small area of the frame on my 1946 Chevy 3/4 ton. I have both hot rolled and cold rolled flat stock. I don't really know the difference between the two, is one easier to weld than the other etc...
Should I be using one of them in particular for this small repair? If someone could educate me just a bit I would appreciate it.

Thanks, Tom

Probably no difference in the steel other than hot rolled will have a little slag/roughness and cold rolled will be clean/smooth with sharp corners. Use the hot rolled for the frame repair and save the cold rolled for something that requires a better looking surface.

Both are likely what's called mild steel. Low carbon content. Like 78buckshot said, use the hot rolled.

My 2 cents. Cold rolled will be stronger because of the process called work hardening. Hot rolling makes the steel more malleable, removing the work hardening from the process. How much stronger that is, is above my pay grade.

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Thanks guys for the comments. I will have to decide which one to use. I will see which one takes less work to fill in the repair area, I know the cold rolled piece fits the area better, but I may save it for a more visible repair somewhere.

Now that you have the steel. Do you know the in's and out's of frame repair? Welding techniques?

If you want advise/suggestions, post a lot of really clear pics of crack, break, and your proposed idea and the metal thickness of frame and repair metal.

You CAN cause more problems.

It's really just some pits in the top flange caused by an old homemade bed that the previous owner put on. The truck apparently sat outside and it would gradually get wet between the top flange and the 4x4 that laid on that flange. I could probably just leave it, but the metal gets a bit thin in a small area. This truck is just used to go to the store once in a while, and a short joy ride now and then. Not going to haul anything heavy on it, got a 2002 Silverado for those jobs.
But to respond to your comments regarding frame repair, I'm sure to properly repair a truck frame one should know what they are doing. The steel type, welding abilities, etc... are all things that should be addressed with importance. If I was using the truck for daily chores, consistently hauling things I would definitely have this looked at by a professional. I am confident I can repair this little area, but I also need to learn more about frame repair, you never know when you might need to do a more extensive repair. Sorry to keep babling on, thanks for your interest in this post. Have a good evening everyone.
Tom

Sounds like the repair I did on my frame. The bed wood laid on top of the frame hump and rusted it away. I welded in a rounded shape to the top flange.

A large truck frame built of alloy steel has special considerations to avoid weakening the frame. But an AD frame is made of mild steel, so as long as you're in a low stress area (like the top flange of the frame hump) there's no special techniques needed. Just make sure you get full penetration and avoid sharp corners. A large truck frame built of alloy steel has special considerations to avoid weakening the frame.

I know many heavy equipment parts are made from A572 steel, that would be a good steel to use for frame repair I'd think. Can always call a frame shop and ask them.

I worked at an outfit that built excavator booms, and car bodies, and mostly used A572 if memory serves.