What Flange?

Today I was trying to figure out the flange size that I should make up for my pump. Its a little confusing at first. You have to get to know your ASAs from your ANSIs( which are the same!) from your ISO-Ks and your ISO-Fs!
Now a 4" ASA/ANSI flange is 9" dia with a 5 and a bit inch hole. Maybe a 3" would be better...
Well to make a mornings research short. I'm going with an ISO fitting.
ISO-F 100 specifically. So here is a rusty piece of 6mm thick mild steel I had knocking around. I got the dimensions from the Net and marked it out.

After a bit of cutting and loads of grinding I got the disk below. I've just drilled the pilot holes for the bolts. I'm going to see if I can find a hole saw a bit less than 100mm to cut the disk from the center.
Looking good so far!

The Diffusion Pump begins

To reach a good vacuum you need a diffusion pump or other fancy pump. I decided that a diffusion pump would be my best bet to make myself so this post is about my progress so far.
It seems its possible to make a pump from copper. But I found that many wonderful shapes and sizes of parts are available for very low prices in stainless steel!In the above image you can see the parts. I think the image is self explanatory! I silver soldered all the parts together with Oxy-acetylene. My soldering getting better as I went along.
I'm planning to put a KF/QF fitting on the top of the outlet to the roughing pump. I've just got to find a brass blank to make it from.This is the thermos lid with the center being cut out. it was thin enough a snips would do it. Below is the M6 SS nut to hold the jet nozzels in place. Its also silver soldered in place. Before I soldered the base on! This will hold the threaded bar which keeps the jets in place.