Is 0.100" wall tube think enough.....

for rear 4-link arms? Or should it rather be 0.120 or thicker?

 

I used 1.25, .095 wall chromemoly. That is what we use in the promod upper rear bars. They use 1.375 lower bars.

 

How much power will be applied? .156 is a safe wall for a hot car.

 

In my experience I use the chrome moly when I weld in threaded ends ,when I want to just direct thread use the .156 wall. The price on the moly with the ends is more than the seamless .156 and should be TIG welded. If you have to hire someone to TIG it may be close to the same.

 

I don't thick its think enough

 

The od of the tubing is a major factor in this case. Scotty's .095 works because of the diameter but is you are direct threading the bars they need to be thicker for both the thread and the fact that the smaller diameter is more prone to bending, especially under braking loads. I woud suggest at least .156 wall for smaller diameter direct threaded bars.

Roo

 

Thanks for the replies guys. I managed to source a length of 1.5" OD with .156 wall at a local steel supplier. Most of the guys don't normally stock that wall thickness. They were actually also the first I tried but also the most likely to have in my region. The next place I would've tried is like about 60 miles away. I must try and get there after work or else before work tomorrow as they only have 4 lengths in stock. At least they're only about 8 miles away from my house.

I will then turn threaded ends for them on my lathe. I've only bought the lathe recently and haven't done anything that "big" yet. Still learning you see.

 

Thanks again guys. Picked up the 21 foot length of tubing this morning before work. Now I'm happy and can continue big time.

Check out my progress thread @ http://www.jalopyjournal.com/forum/showthread.php?t=195096
and tell me what you think.