Picked up the stamping die for the corner glass retainers this afternoon. You can see the test parts pressed from (rusty) scrap 1mm steel sheet. This die is a very complex arrangement with springs and rubber bumps and about 15 seperate pieces. It stamps the shape and the four holes in one hit. I don't know what it weighs but I couldn't pick it up on my own without quite a struggle so I'm guessing about 25kg?

The same place will now make a folding die to bend the four flanges down then we will have a small hand operated press to give the brackets their final curve before sending them off to be powder coated or plated. There is a lot more to a simple corner bracket than most realise (me included).

Looks good, and agree with you there is alot involved in what appears to be a simple part, as in my last job I learnt alot about dies and the design possibilities and constraints of the tool room and they were using 10 tonne up to 60 tonne presses stamping 1mm through to 10mm plate. When you do your next one where possible consider a 2 stage stamp die that could punch in stage 1 and follow through with bends to save on a manufacturing process. The limits will be - it would be very hard to achieve a 90 degree bend but could achieve lesser angles.