best link material?

[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?

[sloshy]

I used 40x40x4 shs with 30x30x3 shs inside.

[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

[v840]

What's your price range?

[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.

[Guy]

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.

[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

[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.

[hiluxmad]

might just buy em.... will look into destruction testing with my engineer

[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

[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.

[v840]

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....

[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

[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.

[MONGREL]

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.

[bulldogy]

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

[uninformed]

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

[Rhett]

6 or 7000 series alloy is the only way to go.

[Willy Hilux]

6 or 7000 series alloy is the only way to go.

I was waiting for you to throw that in.

[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

[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.

[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/

[Slunnie]

Hollow bar should be stronger than solid.

Why

[uninformed]

Hollow bar should be stronger than solid.

Why

because its magic

[MONGREL]

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..

[MONGREL]

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.

[Wendle]

After trying most materials, I will never use anything other than 6061 or 7075 aluminium solid bar again. It is awesome stuff.

[Slunnie]

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.

[bad_religion_au]

what about bizalloy?

or timber?

[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.