Adding strength to flat bar

[B1N9S]

How would you add strength to flat bar, if it was put under twisting strain.

Is the answer to simply buy thicker bar ?

 

[Maker]

Use hollow section.

 

[Screwdriver]

You could put a small crease in it if you have a flypress or access to one.

 

[barracuda816]

Flat Bar is very far from ideal for anything requiring a twisting force, could you replace it with a length of tube? or weld tube to it?

 

[Screwdriver]

To make swages or creases in the metal, I made a tool for the flypress. Chopped up some three inch squares.

Welded up some offcuts, with a slight material gap. Polished them off on the linisher.

Works ok.

Going to have some issues on a long run with runout but I'll come up with a jig for it now I know it works.

For completeness sake and to make operation easier, I tigged a fitting on.

And that was enough to allow me to stamp, stamp, stamp all the way along the strip. Once you have a ding in it, it sort of self aligns.

Bent to match.

Tiggedy tig.

Dressed up the inside but didn't bother too much on the outside, then primered.

I just cut and pasted this from my old van thread. I guess you'll be talking about thicker bar but it's surprising how much difference even a small crease makes in flat metal.

S.

 

[MattH]

Great fabrication there Screwdriver

 

[barracuda816]

What is it for? And how much torque are you expecting?

 

[B1N9S]

What is it for? And how much torque are you expecting?

Not sure if you are asking me ? I have a car rotisserie and need to modify the front mountings. I need about 500mm long arms, to mount to the cars chassis legs. I was thinking of using flat bar, but thought it might be a bit weak.

What is hollow section ?

 

[MattH]

Not sure if you are asking me ? I have a car rotisserie and need to modify the front mountings. I need about 500mm long arms, to mount to the cars chassis legs. I was thinking of using flat bar, but thought it might be a bit weak.

What is hollow section ?

Hollow section = RHS (rectangular hollow section) or SHS (Square hollow section) AKA Box section.

You should be using box for that application I'd of thought.

 

[BrokenBiker]

i would be using RHS

 

[brightspark]

square box-or rectangular box less chance of buckling that solid bar -if u need flat at each end for bolting it to just weld some box to the flat bar-not quite as long

 

[B1N9S]

square box-or rectangular box less chance of buckling that solid bar -if u need flat at each end for bolting it to just weld some box to the flat bar-not quite as long

Great. Thanks guys.

 

[Justme]

I would consider thick bar IF you are going to bolt it to the chassis.
Possibly adding a stiffener to make it a T piece if needed.

The car will provide some of the rigidity.

 

[B1N9S]

I would consider thick bar IF you are going to bolt it to the chassis.
Possibly adding a stiffener to make it a T piece if needed.

The car will provide some of the rigidity.

OK. By 'Thick bar' do you mean thick FLAT bar ?

I think it would be far better if I got some photos. So you guys can see what I mean. I am not an expert as you can tell, but I would like to remain as safe as possible.

As someone once said............I'll be back.