4x2 Equivalent in Steel Section?

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aforjeh

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Hi All

I’m wondering if anyone would know what size/type of steel section (likely a C profile) would be an equivalent replacement for a 4x2 piece of CLS16 timber?

Intended usage would be to form a bed frame. Currently it’s built from 4x2s spanning between sides of a van (around 150cm span), forming left to right supports on the bed. On top of those are three more 4x2s running from head to feet, to which are fixed some bed slats.

I’m wondering if I could replace those ‘left to right’ timbers with steel equivalents, giving a lower profile… with equivalent strength in terms of weight supported on the long side, with the section only supported at the ends.

Thanks

Aaron
 
I suggest a visit to the steel merchants,
To give some idea, might mention I've inquired last fortnight at my local
for the heaviest rectangular box iron I could get, looking to make a post for table saw guard boom thingamabob.
It's gotta be rigid not being affixed at the other end.
Was seeking to get 100x60xthe heaviest gauge I can get...
Best they could find on the computer was 100x50x4mm wall thickness.
7.5 meters for 110 euros (possibly excluding VAT)

I'm going back to see if they have more options for 90x hopefully at least 50, x a heavier gauge than 4mm, and if not I'll inquire elsewhere in the engineering shop where you pay through the nose for short bits.
I might have to go back to the steel merchants. don on the hi-vis, as those forklifters are
flat out, and compare each option by means of sagulation to find the best compromise.


Last time I went before that, I bought some 60x30x of the heaviest gauge they had, possibly 2.5mm
would have to check, 7.5 meters for under 40 euros.
That stuff might be a good choice, having cut it into slightly longer lengths than a bed, I wouldn't
have issue with standing on one, overkill for something being affixed either end.
Here's a link to a list which you could consider what options you have, perhaps they sell C channel also.
I do see they do, but confusing looking dimensions.
https://www.steelexpress.co.uk/structuralsteel/RHS.html

This is another type of c-channel what's out there, not sure what it's called?
Often seen for affixing fuel or gas lines
Its not too visible here, but has folds at the open end to retain fixings.
Perhaps that's an option if you wanted to have it slide out?
SAM_8274.JPG

Hope that helps
Tom
 
Last edited:
Hi All

I’m wondering if anyone would know what size/type of steel section (likely a C profile) would be an equivalent replacement for a 4x2 piece of CLS16 timber?

Intended usage would be to form a bed frame. Currently it’s built from 4x2s spanning between sides of a van (around 150cm span), forming left to right supports on the bed. On top of those are three more 4x2s running from head to feet, to which are fixed some bed slats.

I’m wondering if I could replace those ‘left to right’ timbers with steel equivalents, giving a lower profile… with equivalent strength in terms of weight supported on the long side, with the section only supported at the ends.

Thanks

Aaron
That sounds really heavy for a van conversion?

On my van I have three 4x2 CLS (95x36mm)
Going across the van. they sit in the drink cup holders as it was a minibus.
Then I have 12mm plywood over the top.

In your case you can secure the slats to the 4x2.

Re reading your post what about 2x2 angle. Strong enough and will allow the 4x2 to sit on them?

A picture would help tbh.
 
Currently it’s built from 4x2s spanning between sides of a van (around 150cm span), forming left to right supports on the bed. On top of those are three more 4x2s running from head to feet, to which are fixed some bed slats.

It is currently a three layer construction. Let us say the slats are 20mm high, so overall it will be 220mm.

Raise the left to right to the same level as head to feet, join them in an alternative manner (dominos, dowels, 6" nails, joist hangers, large screws) and you have gained 100mm.
 
alternatively buy something similar to Franklin Black Metal Double Bed Frame | DIY at B&Q As it is only supported on 4 legs it will be strong enough to be strung across the van, as this is essentially no different to being on the 4 legs.

Might need to change the width but should be able to redrill holes on the one side and shorten the cross members, and cut the wood slats.

Looks like it could be quite useful as I think the slats velcro down, so if you ever wanted to use the van without the bed you could lift the slats up. you'd still have a cross member but you'd have full height behind it at least, unless you made the rear cross member detachable then you'd have full access.
 
Steel has a stiffness 10-15 times that of wood, which I think means a 50x100 wood section would equate to a 3.5-5mm x 100 steel section. Using two websites, sagulator for wood and one for a beam you can see that a 4x2 pine at 2000mm and 100kg centre load sags c.4mm a steel box section of 75x25x1.5 at 2000mm with a 100kg centre load sags c.4mm, so is equivalent. Interestingly weight of the two are broadly similar.
 
Interestingly weight of the two are broadly similar.

But all he gains from that stiffness increase is 25mm - the difference between his existing 100mm deep timber and the 75mm deep box section.

A steel shelf angle, horizontal leg at the bottom, with the up and down timbers notched and sitting on top of the leg would gain him 100mm.

He suggests channel in the original post, and this would also do well with the timbers notched to sit on top of the bottom flange.
 
Hi aforjeh. Have a look for "Flitched Beams". It is a structural member you can construct yourself. To produce a 50mm x 50mm flitched beam with a similar bending strength to your present 2x4 timber beam you could consider a member which comprises a central core using a strip of mild steel with a rectangular cross section of 8mm x 50mm which is sandwiched between two timber cheeks of 20mm x 50mm. This composite is locked together by bolts passing through each component. It is aligned with the major dimension of the steel core being vertical. Good luck.
 
It seems to be massively overengineered. There's plenty of van conversion stuff online,if you look at that or just a standard double bed you'll get some better ideas. For a true low profile base a torsion box of 9mm ply with 2 inch batten would be less than 3 inches deep.
 
I suggest a visit to the steel merchants,
To give some idea, might mention I've inquired last fortnight at my local
for the heaviest rectangular box iron I could get, looking to make a post for table saw guard boom thingamabob.
It's gotta be rigid not being affixed at the other end.
Was seeking to get 100x60xthe heaviest gauge I can get...
Best they could find on the computer was 100x50x4mm wall thickness.
7.5 meters for 110 euros (possibly excluding VAT)

I'm going back to see if they have more options for 90x hopefully at least 50, x a heavier gauge than 4mm, and if not I'll inquire elsewhere in the engineering shop where you pay through the nose for short bits.
I might have to go back to the steel merchants. don on the hi-vis, as those forklifters are
flat out, and compare each option by means of sagulation to find the best compromise.


Last time I went before that, I bought some 60x30x of the heaviest gauge they had, possibly 2.5mm
would have to check, 7.5 meters for under 40 euros.
That stuff might be a good choice, having cut it into slightly longer lengths than a bed, I wouldn't
have issue with standing on one, overkill for something being affixed either end.
Here's a link to a list which you could consider what options you have, perhaps they sell C channel also.
I do see they do, but confusing looking dimensions.
https://www.steelexpress.co.uk/structuralsteel/RHS.html

This is another type of c-channel what's out there, not sure what it's called?
Often seen for affixing fuel or gas lines
Its not too visible here, but has folds at the open end to retain fixings.
Perhaps that's an option if you wanted to have it slide out?
View attachment 166334
Hope that helps
Tom
I believe that steel section is known as unistrut
 
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