Zadig,
This was my second purchase from RDG and looks like last.
Here in the U.S., hrs merchant stock steel runs (about) $0.90/lb. 1 lb is (approximately) 3.5 in³ of material. I have a standing "deal" with the local steel yard to purchase most of their 1 X 6 inch, 1-1/2 X 4, and 2 X 4 inch "drops" every month or so. Because I am a "ready purchaser," last month's acquisition ended up running me $0.65/lb. This solves a multitude of "tooling problems" for me and leaves me in control of the final product quality.
I would argue that building such a relationship with your local steel yard is very much a worthwhile effort.
I don't think that I get that good deal, sometimes I get a good price, sometimes I pay premium.
There is one junk yard few kilometres away. I had a day off and spend 100 on steel and I got one 6 m bar of each:
1) dia 20 mm bright steel axle bar, cost me 26 i.e. 1,75/kg or 0,9 USD/lbs
2) dia 25 mm bright steel axle bar, cost me 38 i.e. 1,65/kg
3) 25*25 mm HRS , cost me 32 i.e. 1,09/kg 0r 0,6 USD/lbs
The catch is that hot rolled steel you pretty much know what it is, but lot of steel bars are mystery metal.
I'm making some clamps of my own. One lay I'll buy some flat bars that will do this sort of stuff.
I machined these clamps and they felt very soft, even cheesy. Hope they will be good for something.....I don't use sinkers.
Pekka