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best link material?
Posted: Tue May 25, 2010 6:06 pm
by hiluxmad
who uses what?
was looking at 36/16 hollow bar but there has to be something better?
what about 32nb heavy? or the equivalent spec'd tube
suggestions?
Posted: Wed May 26, 2010 12:10 am
by sloshy
I used 40x40x4 shs with 30x30x3 shs inside.
Posted: Wed May 26, 2010 8:32 am
by uninformed
by hollow bar do you mean stuff like euro-norm. If so I believe that it is a better grade the CHS black pipe.....
Serg
Posted: Wed May 26, 2010 9:16 am
by v840
What's your price range?
Posted: Wed May 26, 2010 9:28 am
by hiluxmad
my local bloke quoted $75/m on trhe hollow bar so any where around there really.
not to fussed on price just want it to be strong and to pass engineers.
Posted: Wed May 26, 2010 9:44 am
by Guy
hiluxmad wrote:my local bloke quoted $75/m on trhe hollow bar so any where around there really.
not to fussed on price just want it to be strong and to pass engineers.
In that case I would be speaking to your engineer .. Tell him what you have in mind and see what he says.
Posted: Wed May 26, 2010 9:46 am
by duncan
Ive made a heaps of solid lowers out of 4340 chrome molley 40mm dia good size to drill and tap to take most joints on the market.Uppers just used some 1 inch shed 80 or 1 1/4 .
With the lowers being solid you can use them as sliders when driveing up rock shelves with no worries about bending them.
Duncan
Posted: Wed May 26, 2010 9:51 am
by v840
I appreciate you're in Vic, but just as a heads up, my engineer here in NSW has said that my home made links must be Non Destruction Tested (~$100) in order to be passed. Professionally made links , such as Superior's, are passable without NDT.
Not a huge deal if your welds are good but just something else to be aware of.
As love_mud says though, speak to your vagineer first.
Posted: Wed May 26, 2010 11:23 am
by hiluxmad
might just buy em.... will look into destruction testing with my engineer
Posted: Wed May 26, 2010 1:31 pm
by DIRTY ROCK STAR
The material i use is 12mm wall hollow bar.
depending on the length, weight of truck and use, i would go more heavy or better material.
i reckon duncan might be onto it, i saw how he drove his lux at Tufftruck and for them not to bend is a good effort.
i bought some off a store once(advertises in magazines so you would think they had decent gear), and they broke heaps easy (15mins use), costing me a new diff and alot of grief. but it wasnt superior. Their gear is as good as it gets from a shop.
and yeah testing is a pain in the ass
Posted: Wed May 26, 2010 1:49 pm
by sierrajim
I believe that non destructive testing would be a chack on the welds. Gwagensteve would be the best one to talk to about who and where for this.
Posted: Wed May 26, 2010 1:52 pm
by v840
sierrajim wrote:I believe that non destructive testing would be a chack on the welds.
This is what I was lead to believe. I appreciate it's not really relevant to what materials he uses but the fact that he asked about materials does suggest he is planning on building his own so I was just throwing up another thing that may be worth thinking of....

Posted: Thu May 27, 2010 1:07 am
by duncan
If you do go with 4340 the welding inspector at work advised me to pre heat to 124 degrees or straw color then weld with low hydrogen rods then post heat or at least let cool naturaly .Most I have done this way some I have just used a 13s rod with a bit more amps to burn in never had one fail yet just do a root run then cap with a weave over the top or you could go for a 3 run fillet
Duncan
Posted: Fri May 28, 2010 1:45 pm
by nzdarin
If you use the right type of bar (size) for the joints you are using then there is no welding anyway. The ones I'm building will just be threaded and then use a lock nut.
Posted: Fri May 28, 2010 10:55 pm
by MONGREL
duncan wrote:If you do go with 4340 the welding inspector at work advised me to pre heat to 124 degrees or straw color then weld with low hydrogen rods then post heat or at least let cool naturaly .Most I have done this way some I have just used a 13s rod with a bit more amps to burn in never had one fail yet just do a root run then cap with a weave over the top or you could go for a 3 run fillet
Duncan
Shouldn't chrome molly be welded with TIG only to reduce the heat affected zone? Which will alter properties and cause failure in that area?
Have read it needs to be heated to a stupid temp like 400degC and cooled VERY slowly (bucket of lime) to be welded with low hydrogen rods.
I have a radius arm i made in the shed, im worried about using it because the pin that mounts to chassis (GQ) is from 4140. Pre heated and cooled in heat blanket, but im not sure about it.
Posted: Sat May 29, 2010 6:18 am
by bulldogy
MONGREL wrote:duncan wrote:If you do go with 4340 the welding inspector at work advised me to pre heat to 124 degrees or straw color then weld with low hydrogen rods then post heat or at least let cool naturaly .Most I have done this way some I have just used a 13s rod with a bit more amps to burn in never had one fail yet just do a root run then cap with a weave over the top or you could go for a 3 run fillet
Duncan
Shouldn't chrome molly be welded with TIG only to reduce the heat affected zone? Which will alter properties and cause failure in that area?
Have read it needs to be heated to a stupid temp like 400degC and cooled VERY slowly (bucket of lime) to be welded with low hydrogen rods.
I have a radius arm i made in the shed, im worried about using it because the pin that mounts to chassis (GQ) is from 4140. Pre heated and cooled in heat blanket, but im not sure about it.
120* and cooled in a heat blanket is all that is required
Posted: Sat May 29, 2010 10:15 am
by uninformed
duncan wrote:Ive made a heaps of solid lowers out of 4340 chrome molley 40mm dia good size to drill and tap to take most joints on the market.Uppers just used some 1 inch shed 80 or 1 1/4 .
With the lowers being solid you can use them as sliders when driveing up rock shelves with no worries about bending them.
Duncan
WTF??? Solid??? wow, i though guys in the USA were making them out of 4340 or similar and only 3-6mm wall???
Serg
Posted: Sat May 29, 2010 7:52 pm
by Rhett
6 or 7000 series alloy is the only way to go.
Posted: Sun May 30, 2010 7:45 am
by Willy Hilux
Rhett wrote:6 or 7000 series alloy is the only way to go.
I was waiting for you to throw that in.

Posted: Sun May 30, 2010 7:54 am
by duncan
The solid bar is cheap have run this set up on quite a few peoples rigs no failures no matter how hard you hit them.Actually had one guy bend a 32mm diameter lower front bar on a 5 link I built when he dropped the hole weight of a short wheel base GQ on it after driveing of a rock .That was a quite short arm as well but the weld was fine.
Ally would be cool nice and light but more expensive and unless you can mig or tig weld then limited to what you can do unless you get someone to make them up for you.
Duncan
Posted: Sun May 30, 2010 9:55 am
by hiluxmad
want to use nissan bushes so will have to be welded on the ends.
could you use 32nb(or similar in seamless) with say a 6mm wall?
still waiting to get on to my engineer about what he wants.
just asking out of interest.
Posted: Sun May 30, 2010 11:45 am
by Willy Hilux
Here's a site to get some good sizes of hollow bar etc. Hollow bar should be stronger than solid.
http://www.interlloy.com.au/
Posted: Sun May 30, 2010 7:22 pm
by Slunnie
Willy Hilux wrote:Hollow bar should be stronger than solid.
Why

Posted: Sun May 30, 2010 7:25 pm
by uninformed
Slunnie wrote:Willy Hilux wrote:Hollow bar should be stronger than solid.
Why

because its magic

Posted: Sun May 30, 2010 8:24 pm
by MONGREL
bulldogy wrote:MONGREL wrote:duncan wrote:If you do go with 4340 the welding inspector at work advised me to pre heat to 124 degrees or straw color then weld with low hydrogen rods then post heat or at least let cool naturaly .Most I have done this way some I have just used a 13s rod with a bit more amps to burn in never had one fail yet just do a root run then cap with a weave over the top or you could go for a 3 run fillet
Duncan
Shouldn't chrome molly be welded with TIG only to reduce the heat affected zone? Which will alter properties and cause failure in that area?
Have read it needs to be heated to a stupid temp like 400degC and cooled VERY slowly (bucket of lime) to be welded with low hydrogen rods.
I have a radius arm i made in the shed, im worried about using it because the pin that mounts to chassis (GQ) is from 4140. Pre heated and cooled in heat blanket, but im not sure about it.
120* and cooled in a heat blanket is all that is required
This is from inter alloy web site
Welding
Welding of 4140 in the hardened and tempered condition (as normally supplied), is not recommended and should be avoided if at all possible, as the mechanical properties will be altered within the weld heat affected zone. It is preferred that welding be carried out on 4140 while in the annealed condition, and that the work piece, immediately on cooling to hand warm, is then stress relieved at 595 oC - 620 oC prior to hardening and tempering.
If welding in the hardened and tempered condition is really necessary, then the work piece, immediately on cooling to hand warm, should be if possible stress relieved at 15 oC below the original tempering temperature (if known).
Welding Procedure
Welding of 4140 in whatever condition should always be carried out using low hydrogen electrodes - please consult your welding consumables supplier.
Suggested pre-heat temperature
Section oC
25 mm 370
40 mm 400
50 mm 425
75 mm 455
150 mm + 510
Post Welding
Maximum cooling rate 95 oC per hour down to 95 oC, follow by cooling in still air. N.B. No draught. It is recommended that the work piece if possible is wrapped in an heat resistant blanket or buried in sand etc..
Posted: Sun May 30, 2010 8:31 pm
by MONGREL
hiluxmad wrote:want to use nissan bushes so will have to be welded on the ends.
could you use 32nb(or similar in seamless) with say a 6mm wall?
still waiting to get on to my engineer about what he wants.
just asking out of interest.
Pretty sure most people go alot heavier wall. Think i read superiors are from a heavy wall hollow bar. 40od cant rember the id. Was a link on here somewhere which told you what they are made from.
Edit; This is from superior site.
Lower control arms are manufactured from High grade Mecavel Hollow Bar 40 od x 25 Id DOM Pipe. Strongly recommended to replace the standard items as they are extremely weak and once bent the pinion will snap. Finished in a zinc anti corrosion finish and fitted with high flexing rubber bushes. Sold in standard GQ length and as a pair.
Posted: Sun May 30, 2010 8:49 pm
by Wendle
After trying most materials, I will never use anything other than 6061 or 7075 aluminium solid bar again. It is awesome stuff.
Posted: Sun May 30, 2010 9:01 pm
by Slunnie
MONGREL wrote:bulldogy wrote:MONGREL wrote:duncan wrote:If you do go with 4340 the welding inspector at work advised me to pre heat to 124 degrees or straw color then weld with low hydrogen rods then post heat or at least let cool naturaly .Most I have done this way some I have just used a 13s rod with a bit more amps to burn in never had one fail yet just do a root run then cap with a weave over the top or you could go for a 3 run fillet
Duncan
Shouldn't chrome molly be welded with TIG only to reduce the heat affected zone? Which will alter properties and cause failure in that area?
Have read it needs to be heated to a stupid temp like 400degC and cooled VERY slowly (bucket of lime) to be welded with low hydrogen rods.
I have a radius arm i made in the shed, im worried about using it because the pin that mounts to chassis (GQ) is from 4140. Pre heated and cooled in heat blanket, but im not sure about it.
120* and cooled in a heat blanket is all that is required
This is from inter alloy web site
Welding
Welding of 4140 in the hardened and tempered condition (as normally supplied), is not recommended and should be avoided if at all possible, as the mechanical properties will be altered within the weld heat affected zone. It is preferred that welding be carried out on 4140 while in the annealed condition, and that the work piece, immediately on cooling to hand warm, is then stress relieved at 595 oC - 620 oC prior to hardening and tempering.
If welding in the hardened and tempered condition is really necessary, then the work piece, immediately on cooling to hand warm, should be if possible stress relieved at 15 oC below the original tempering temperature (if known).
Welding Procedure
Welding of 4140 in whatever condition should always be carried out using low hydrogen electrodes - please consult your welding consumables supplier.
Suggested pre-heat temperature
Section oC
25 mm 370
40 mm 400
50 mm 425
75 mm 455
150 mm + 510
Post Welding
Maximum cooling rate 95 oC per hour down to 95 oC, follow by cooling in still air. N.B. No draught. It is recommended that the work piece if possible is wrapped in an heat resistant blanket or buried in sand etc..
This is the exact thing that worrys me. Someone was making these from 4140 before and when I asked about pre/post treatment was told "they're all good slunnie". Not good enough for me, especially if they crack.
The set I made were low carbon steel 50OD 25ID (12.5mm wall) with Patrol bushes at either end. These weld well, are not heat affected and bend rather than brittle fail.
Posted: Sun May 30, 2010 9:10 pm
by bad_religion_au
what about bizalloy?
or timber?
Posted: Sun May 30, 2010 9:10 pm
by Rhett
if you want to run patrol bushes, tap the ally and weld some thread to the bush tube. It is not all that expensive for 7000 series ally.