Aluminium grade ?

[Smallfry]

I know this is a "how long is a piece of string" question, but .......

I have a commercially available engine adaptor plate, to put an alien gearbox on it. I need to sleeve some holes down in it, and want to buy some tube in the same material if possible. I wondered if there is any way to tell what grade of material it is, there are no marks on it, and the original supplier does not want to tell me, which I guess is fair enough, due to intellectual rights or whatever.

Failing that, anyone have any idea what grade/s are most likely to be used ? It is 20mm thick, if thats any help.

 

[julianf]

I would imagine a 6000 series. If you really want to know, take it to your local scrap yard, and get them to gun it.

 

[Munkul]

It's likely either 5083 or 6082, just because those alloys are common for machining, but really it could be anything at all. If your shrink fitting sleeves in, why does it matter?

 

[Smallfry]

It's likely either 5083 or 6082, just because those alloys are common for machining, but really it could be anything at all. If your shrink fitting sleeves in, why does it matter?

I just thought it might be better with the right grade.

Plate is 20mm thick, and has holes 14mm dia, but these holes have been counterbored to 19mm dia, and 17mm deep, in order to take socket head cap screws, and have the tops flush with the surface. This leaves, at the bottom of the hole a step 2.5 each side and 3mm thick, and I have no confidence this is strong enough. So what I want to do, is insert some bushes into the counterbores to bring the 14mm diameter up to the plate surface.

Then I can use flanged bolts, which have a 26mm diameter under the head, to spread the load out onto the surface of the plate.

I do not understand why it has been done the way it has, because the surface fitting bolts will not interfere with anything.

Hope this makes sense.