how much did you pay for your seamless 19mm and 25mm for the wishbones and trailing arms?
have phoned around a few suppliers and no one does it around here (south wales) but they all said its expensive!!
can you get aero section in seamless??
i looked for some too, to no avail.
i ended up getting 25mm x 2mm wall ERW. according to recent posts, there is no major differrence provided that you weld plates etc over the seam, to
strengthen it. believe what you will about that one though, but it makes sense to me. 
by plates, i dont mean additional plates, just the bone plates...
[Edited on 7/2/05 by JoelP]
FWIW,
Seamless tubing, or DOM as it's called here, is very expensive compared to ERW tubing. Safety comes first of course, but I've never
seen anyone post here that their ERW a-arms failed.
what size erw are people using for the bones then???
i know safety comes first but closely followed is budget!
the commonest recommendation is 25x2mm. i have driven on 19mm 16g square bones with no ill effects, but i reckon a few bumps would redesign them a
bit! i bought the 25x2 to make new bones over winter (running out of time now though!).
more important is design, and make sure you know about stress raisers.
remember, a bent bone is better than a bent chassis!
I guess that came across a bit strong. When I say seamless is much more expensive, it is... about 5X last time I checked, but you don't need *that* much tubing for a-arms.
check the RS catalogue for seamless steel hydraulic tubing, not cheap, but available!
I used 3/4" hydraulic tube for my front wishbones on the first set I made some years ago, no probs.
thanks NS Dev - will look into that.
gonna look into industrial heating pipe aswell. i know its mild steel seamless but not sure of dia and wall thickness. -will keep you posted.
try here for small quantities for seamless tubing
I got mine from a local shipbuilder, and, as NS Dev says hydraulic fabricators use loads of the stuff.
As it's expensive try to source offcuts, mine cost me a tenner
Mick
from RS components (v. expensive but very convenient if you are in the middle of nowhere!) 20mm x 2.5mm hydraulic tube is £5.40 a metre.
West yorshire steels are the best place for bigger quantities, though it is expensive. I got all my chassis tubing from them last year and even then a
6' length of 1" tube was £30 and thats before the privces went nuts.
Be careful with DOM hydraulic tube, this isn't necessarily the same as CDS - when I enquired with WYS they said that DOM hydraulic tube was far
more prone to bending that just CDS.
http://www.westyorkssteel.com/
got mine from a gas pipe supplier around £70 for 2 x 6m length but I also used it for the rear IRS wishbones.
quote:
Originally posted by Matthew_1
West yorshire steels are the best place for bigger quantities, though it is expensive. I got all my chassis tubing from them last year and even then a 6' length of 1" tube was £30 and thats before the privces went nuts.
Be careful with DOM hydraulic tube, this isn't necessarily the same as CDS - when I enquired with WYS they said that DOM hydraulic tube was far more prone to bending that just CDS.
http://www.westyorkssteel.com/
The 6' I bought was a heavier guage - that stuff was 12swg which maybe why the hike in price? But even at 16swg it's still way more
expensive that ERW.
I'm not convinced by the "all mild steel" argument implying ERW and CDS are the same, I know it's all basically steel, but
whatever treatment is performed certainly make the CDS far tougher to work than ERW. When notching fishmouths it was also pretty obvious that the CDS
was a harder metal than the ERW.
I'm certainly no expert on this and the above is just an observation from working both types of tube, but the end products of CDS and ERW
can't be just down to one being welded and one not?
basically yes, in very simple terms!!
They are both mild steels, ERW will almost certainly be made from a lower grade of mild steel, meaning less control during steelmaking but still the
same or similar basic properties.
The main difference is in the process of manufacture. To make ERW you can buy a mill for a few million quid and start, your raw material is basic
steel strip which is dirt cheap on world markets.
To make seamless you start with a solid round billet, and then make a hole in it, which ain't cheap whichever way you do it!! At Timken Desford
(formerly Desford Tubes/TI Tubes) where I work, we have a machine called a "2 roll barrel piercer" which cross rolls a billet preheated to
1250 deg C and forms it over a piercing plug tipped with nimonic alloy. This pierced bloom is then rolled on a "Transval Elongator" to thin
the wall and form the bore, and then rolled through 3 more major operatins, before heat treatment, pickling, NDT operations including ultrasonic wall
thickness measurement, laser OD measurement, ultrasonic wall/bore defect tests, eddy current od defect tests, and then to make the tube that you are
using, it is cold reduced in a further machine to give the bright finish and better structure. A hot seamless tube mill is not a small investment (to
be honest I have no idea how much to build one, but our main furnace would cost over a million to refurbish, and to give some idea of scale at this
level, Corus are spending 250 million on their facilities in Rotherham!
I used to drive a fork truck loading stainless billet into a small rolling mill from the radiac saws.It used to go from there to the reeling shop to
straighten and size it. It used to ship all over the world, Germany, America and Japan till British Steel bought it and shut it down. I also worked in
a foundry where we used to spin down hole drill tubes. That was entertaining when the end plates weren't caulked properly. It was like a 60'
Catherine wheel. We used to have a skip tipped up on its side to dive into till it ran out or set
So is ERW not recommended for wishbones then or are some people using it?
Mark
You might have dealt with some of our products then Pete, we supply a lot of oilfield tubing (mainly mechanical stuff like 4140 Q+T tube for couplers
etc) but our plant has been a major supplier of this sort of stuff for around 60 years now!
Incidentally, we used to have 3 hot mills, and one of those was sold off in the early eighties to a Czech manufacturer for rolling stainless seamless
tubing!
hi chaps i have just formed the rear hoop and lower corners out of 18mm tube from steel supplied from my local hydraulic supermarket, as it fitted the pipe bender better than the 19mm the book recomends, they have offered to supply me with of cuts to make my wishbones for 10 beer tokens, am i correct in thinking i need 25mm x 2mm wall thickness for making w/bones and which inserts/bushes do you recomend the cheapest poly type appear to come from robin hood cars "LOLOCOST" range? regards martin
quote:
Originally posted by Matthew_1
The 6' I bought was a heavier guage - that stuff was 12swg which maybe why the hike in price? But even at 16swg it's still way more expensive that ERW.
I'm not convinced by the "all mild steel" argument implying ERW and CDS are the same, I know it's all basically steel, but whatever treatment is performed certainly make the CDS far tougher to work than ERW. When notching fishmouths it was also pretty obvious that the CDS was a harder metal than the ERW.
I'm certainly no expert on this and the above is just an observation from working both types of tube, but the end products of CDS and ERW can't be just down to one being welded and one not?
quote:
Originally posted by kaymar
am i correct in thinking i need 25mm x 2mm wall thickness for making w/bones
The essential thing is to understand the material you are working with, ERW its ultimate failure point is weaker than equivalent drawn seamless tube
but its composition is ideal for welding. Depending on the composition drawn tubes may or may not be suitable for welding.
Even with cds which is suitable for welding in the heat affected zone adjacent to the weld the heat of the welding process is very likely to reduce
the mechanical properties to close to those of a weld in erw.
The book design of lower wishbone isn't great and if corners are cut durring its fabrication it will result in a weak wishbone, much better
design are around in which the mechanical strength and stiffness of the tube is much less critical -- all the on the ball Locost suppliers are now
making/supplying parts for this type of wishbone.
My own lower wishbone use 22mm thick wall ERW built on plates supplied by Darren.
The seam is aligned with the centre line of the plate which set on the neutral axis of the tubes.
quote:
Originally posted by Matthew_1
The 6' I bought was a heavier guage - that stuff was 12swg which maybe why the hike in price? But even at 16swg it's still way more expensive that ERW.
I'm not convinced by the "all mild steel" argument implying ERW and CDS are the same, I know it's all basically steel, but whatever treatment is performed certainly make the CDS far tougher to work than ERW. When notching fishmouths it was also pretty obvious that the CDS was a harder metal than the ERW.
I'm certainly no expert on this and the above is just an observation from working both types of tube, but the end products of CDS and ERW can't be just down to one being welded and one not?
Blimey, I seem to have been heavily quoted here!
Again this is going on experience, both ERW and CDS weld up just fine (obvious really!), and the majority of my chassis is round CDS (it's not a
'book' chassis) so there's no "mixing problem".
Another observation though is that CDS does tend to weld with less "holing" than ERW, that point where you weld with just a tad too much
power and go right through, which I've tried to avoid totally but it does happen now and then - it seems like you're able to weld at a
higher power and get neater welds than similar thickness ERW. Again, just an observation - I've seen the arguments on here!!!
That might just depend on the thickness, but above that, although the actual grade of steel may be the same for the two, the specs at this level are quite wide and steel cleanliness not always that well tied down in the spec. The strip used for the ERW tube will no doubt be nearer the "worse end" of these limits than the billet used for the seamless, and steel cleanliness can affect weld quality quite dramatically.