I have read through a lot of the posts under this topic and have some thoughts. Just my ideas on the topic.
For many, myself included, there is a certain thrill in making something from "found" material. Many times this works out well. Sometimes it doesn't. I made some parts yesterday from some found 3xx SST. The money I saved in materials did not come close to the cost of the three broken taps and the time spent (unsuccessfully) trying to remove them and I ended up making the parts over from aluminum which was easier to work and adequate to the task. I picked the stainless because it was closest to the finish OD I needed. The point here is that there is often value in knowing what you're working with. A crankshaft made from cold rolled steel will likely warp. Cast iron from sash weights may be full of inclusions which may not matter or may be very annoying as a void in your cylinder wall. There are lots of suppliers of small lots of material and I'm sure many of you have a favorite based on price, delivery speed, helpfulness or whatever. I order a lot of my material from McMaster Carr (www.mcmaster.com)because I find them easy to deal with and they offer a great variety of materials of all kinds (even balsa wood). Whether you choose to deal with them or not, their on line catalog (or paper if you can get one) has a great intro to each type of material listing its characteristics relative to others in its family. This is not a course in metalurgy, but it can give one a pretty good idea of what to look /ask for regardless of the ultimate source. For example, in the aluminum section it covers hardness, yield, weldability, corrosion resistance, formability/workability, and machinability. This kind of info can save you from making a part from 2007 alloy (great machining) only to find that it cannot be welded when you go to put it together. If you get your material at a scrap yard sometimes you can find drops and off-cuts from local shops that still have the type markings on them. This is good info.
Enough, I've rambled too long.
For many, myself included, there is a certain thrill in making something from "found" material. Many times this works out well. Sometimes it doesn't. I made some parts yesterday from some found 3xx SST. The money I saved in materials did not come close to the cost of the three broken taps and the time spent (unsuccessfully) trying to remove them and I ended up making the parts over from aluminum which was easier to work and adequate to the task. I picked the stainless because it was closest to the finish OD I needed. The point here is that there is often value in knowing what you're working with. A crankshaft made from cold rolled steel will likely warp. Cast iron from sash weights may be full of inclusions which may not matter or may be very annoying as a void in your cylinder wall. There are lots of suppliers of small lots of material and I'm sure many of you have a favorite based on price, delivery speed, helpfulness or whatever. I order a lot of my material from McMaster Carr (www.mcmaster.com)because I find them easy to deal with and they offer a great variety of materials of all kinds (even balsa wood). Whether you choose to deal with them or not, their on line catalog (or paper if you can get one) has a great intro to each type of material listing its characteristics relative to others in its family. This is not a course in metalurgy, but it can give one a pretty good idea of what to look /ask for regardless of the ultimate source. For example, in the aluminum section it covers hardness, yield, weldability, corrosion resistance, formability/workability, and machinability. This kind of info can save you from making a part from 2007 alloy (great machining) only to find that it cannot be welded when you go to put it together. If you get your material at a scrap yard sometimes you can find drops and off-cuts from local shops that still have the type markings on them. This is good info.
Enough, I've rambled too long.
