I'm need a 5" x 5" x 1" block of aluminium. Is this something I can buy online and are there different types of aluminum to consider? Will I have to buy a bigger piece and cut the aluminum down to my specific size?
I need a solid base that I can tap with hole to mount into a DIY slider dolly.
There are several online metal suppliers that will also make custom cuts. Online Metals is one that I have used. There is a minimum length that you must order (usually 1 ft) and a charge per cut. Depending on where you live you might also find a local metal supplier that can do the same for you.
Wherever you order, I'd suggest you get two 5" pieces cut from 1ft of 1" x 5" bar and then you'd have a spare. I would definitely try to have someone else do the cutting for a piece that size. Rectangular tubing might also be something to consider.
Here is a reference on the same supplier for the aluminum alloys they stock. Be sure to check the prices as they'll vary, but I believe 6061 is one of the more widely used alloys.
It's a little wierd to use such a thick block of metal for anything (except making a die or something), so you may want to rethink your design, whatever it is.
I would definitely check eBay first, because it will be a LOT cheaper than going to a metal shop. BTW the kind of dealer you want is called "non ferrous".
Some places will sell off cuts and scrap by the pound and once again that will be a lot cheaper than buying it custom. You do not say where your location is in your profile, so not sure what dealers are in your area.
As Jay says, get a pro to cut it, because setting up to cut metal, while not terribly difficult, sounds like it is beyond your skill level right now.
As for the type of aluminum, I wouldn't worry about it for something like this.
