aluminium

[jonjoe]

hi in technology i am making a dvd stand and needs a plate which it bolted to the wall and a piece of box section coming out of it not very big. i though first of to get a piece of 3mm plate and some small box section and just weld it on but my teacher said it has to be flat pack and so says if you put a bit of plate on top of the first plate to make it 6mm just in the centre and use soild box section and round the end in the lathe and drill a hole in the plate and tread the rounded box section they would both screw in. i thought yea that might work and I get to weld but now he saying to make it out of aluminium but i don't think it will work.

he has a ac buzz box and to use aluminium rods you need dc he doesn't know stick welding aluminium is a pain.

also I don't think aluminium will be strong enough but all he cares about is about it ascetic properties and not that it will bend.

finally my question is if i did use aluminium would rounding it in a lathe even work and can you thread aluminium.

i will try to persuade him to mild steel again.

 

[piman]

Hello Jonjoe,

yes you can turn aluminium and also thread it, but it is not very strong. It is better to use steel box section and fit a threaded insert in the end, and using a countersunk screw screw through the back of the plate into the box section. Box section steel will be as light or lighter than solid aluminium.
Also, I don't see how aluminium, looks better than steel?

Alec

 

[jonjoe]

yea i know he said

oh teenagers are attracted to bright colours i said yea then paint it and he said something like aluminium is nice and shiny. and im like oh great

i spent like the last 3 weeks trying to stop him from using aluminium

 

[piman]

Hello Jonjoe,

aluminium, unless it it either regularly polished or clear lacquer is applied will not stay shiny for long.

Alec

 

[jonjoe]

thanks

 

[hotrodder]

Aluminium is a lot easier to cut/machine/tap threads in than mild steel. Asthetics are a personal thing but both ally and mild steel will need something to keep their finish even indoors... various waxes and sealants like automotive stuff will last pretty much forever indoors, left bare ally will dull off very slightly indoors and fingerprints will locally tarnish it and if you try hard enough make your hands dirty

Very generally ally is around a third the weight (density) of steel, 1/3 the stiffness and (for the aluminium alloys used as solid bar) about 1/2 the strength of mild steel. On the other hand it's a DVD stand...

Stainless wouldn't need any finishing as it provides its own (assuming a polished or brushed finish is what you want) but is more expensive and harder to cut/machine/thread than mild steel