3.2mm High Yield Tube vs Standard 4mm Tube

Alan Reade said:
I represented SGB in a meeting around 10 years ago on this subject.
A large midlands Scaffolding company who had a close relationship with a Large Midlands Building Contractor had convinced them the only way forward was 3.2mm high grade steel.As a result the Builder was only going to allow scaffs with 3.2mm to quote their work.

It is a long time since I looked at this however I recall that whilst 3.2 was stronger in bending in was weaker in compression, the bending capacity allowed you to span further but the compression meant your standard was weaker and had to be at closer crs. so no real gain.

The gain was high for the scaffs as the kit was lighter.
There was an obvious gain for the scaff as steel is priced by the tonne which resulted in cheaper kit and less transport plus volume gains through the scaffs.

There may be a couple of other factors to consider,
1) the mixing of kit, you must design all your scaffolds to your weakest components.
2) 3.2 was not covered in BS5973 nor I believe in TG20:08 (it may be in TG20:13 no idea) which would make all scaffolds design jobs.

At the meeting I stated that SGB would not be converting to 3.2mm to suit the builder as the their kit was 4mm. Benchmark then followed suit.
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Seems to me ,if centres have to close in a bit,you would still be better off using this kit.
 
If it's not covered by bs or tg you would need a design for every job. Seems a potential nightmare to me Fred.
 
Surely not once the calcs have been agreed. Light ,med, heavy duty. Generic I would think
 
Yeah, maybe Fred. I think it could pose a problem for some though. If it's not covered by any design standard it would be similar to the double enders and need testing and it's own yie pattern that would need to be proven.

I've probably been a bit brainwashed but it would concern me a bit. :embarrest:
 
Hi Frederick personally I thought 3.2mm was to fall in line with weights and measures in relation to reducing the weight in manual handling bring it in line with European law and the only difference between 3.2mm an 4mil is you have to close your bays in and always thought 4mil as a tendency to bend but 3.2mm can snap under too much compression I have worked with both and all I can say is tube is tube its all squares if its lighter its a bonus
 
no fella never seen one snap but seen plenty of jobs up that should have snapped I do know there is one fitting that 3.2mm its not compatible with and that's band an plate mind you though Frederick it makes a nice hole to store your polos in ?
 
it does when people over torque the plate they even make an indentation on 4mm benjo
 
frederik said:
Seems to me ,if centres have to close in a bit,you would still be better off using this kit.
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It's clearly a good product and the right way to go but..........................
only if you start out with it, if you have 20,000 tonne of 4mm you would think differently I'm sure

---------- Post added at 05:10 PM ---------- Previous post was at 05:07 PM ----------
steelcitycowboy said:
it does when people over torque the plate they even make an indentation on 4mm benjo
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B&P used to leave a nipple on 4mm if over tightened. This was first noticed as a problem when we first started to use Cuplok jacks (designed for 3.2mm tube) in 4mm tube for supports. Once the B&P had been tightened and a nipple formed it was a ba5tard to get the jacks out of the tube
 
how much are we talking when making the bay's shorter? I've always tried to stick to 6ft anyway for piece of mind, 5ft on new builds.
 
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