Strength of 3 inch C channel???

[cstew47]

I have done a lot of structural design work and I am very confident that you are ok with the structure that you built. Also, you have to understand that there are five available sizes of 3 inch channel. They are rated by lbs/ft of weight. It's difficult to identify which you have unless you can talk to the supplier. The lightest is 3.5 lbs/ft. 4.1lbs is also very common and is much stronger. What Bextreme said is very true. You are dealing with live load figures that will never equal the total weight at the weakest point.

 

[Matt69olds]

i had forgotten I started this thread.

I had to move my brother in laws 96 1 ton Ram dually, the ramps didn’t flex at all. I’m guessing that’s a good sign.

He bought the truck and drove it for the first 600 miles trouble free. It quit running when it ran out of fuel. He said he filled it when he first bought it. I commented “you didn’t think anything was wrong when the fuel gauge didn’t move when you filled it, and after 600 miles it still didn’t move?!

I would think if the gauge showed 1/4, showed a 1/4 tank AFTER filling it, and 600 miles later it still showed 1/4, the gauge probably isn’t right!! A new sending unit got him going.

 

[Paladin]

When in doubt, Always use OverKill!!!

 

[AuroraGirl]

7ft is a fairly long ramp. I'd imagine that if you were to load up a 9600lb truck again, you may see the ramps flex a little bit. But I doubt it would actually bend them. Just don't hit them with speed and they should be fine.

i put 4x4 wood on the ground and support my long ramps because a4000 pound car would almost definitely bend it baddd like eough to slip down the thing but when supported in middle oddly works fine. ive used firewood to do that too. a larger 9600 pound beast tho, oh i wouldnt do that. long is definitely at disadvantage if not built right.

 

[Ricko1966]

As @bucket said. Get you a couple wooden blocks that fit up under where you joined the old and new, you should be golden.

I was going to suggest adding braces there,that bolt to the sides of the ramp and can be flipped down to brace the ramp,similiar to a motorcycle center stand. Weld on plate on the outside of the channel to attach them.