Does square/rectangle machinable steel cost more than AL and have little variety?

I just ran a batch of milled parts using some 12L14 square bar which I had on hand from long ago. When I went to buy more, I was surprised to find it 1/2 again more expensive than similarly shaped AL 6061, at least in small lots on the web. As I started looking at steel prices and availability, I found few highly machinable alloys in square/rectangle bar (1018 is common but not a lot else; some 11L17 or 1117) and prices generally higher than aluminum. There is more variety and availability in round rod and I've bought 12L14 for turning with no problem. Am I just looking in the wrong places? Is there no market for steel for milling prismatic shapes other than 1018?

Buying from online suppliers like metalsdepot or others is very expensive. Mostly for hobby use or $$$ convenience. I do look there often to get a rough idea, but my local supplier kicks their prices in the butt. And free delivery. But a forklift is needed to unload what I buy.

Round Bar is always much cheaper then square stock as less processing is required. thus less $

I think steel alloys with very good machinability are mostly used in round bars and to a much lesser extent, square and hex bars. These are shapes that are suited to automatic bar feeders and collets. Used to be automatic screw machines, now lots of CNC lathes add to the mix of rapid production machines that need fast easy machining alloys to reduce cost. Fast machining offsets the additional cost of the alloy. But that cost saving is only realized in large quantity orders, not buying by the foot online and paying UPS shipping.

When I was doing production jobs, I used lots of 12L14 round bar in my Hardinge hand turret lathe. One part needed rectangular bar and was all milling and drilling. I found that 12L14 was not available in that size/shape bar and had to use 1018.

Larry

Agreed. The more machinable alloys are round stock as these are the ones that get fed through lathes, Swiss', and screw machines. You can find other shapes tho, from places like Admiral, Jorgenson, etc.

In a world where modern tools and tool path strategies allow you to haul ass through Inconel and other super alloys. I have to wonder. Is it really that big of a deal to make these parts out of 1018 instead of 12L14?

I would avoid 1018 like the plagues, unless it was super open tolerances. 12L14 or 1144, or Niagra stressproof will cut sooooo much nicer, but it rusts easily so need to keep up on wiping it down, or using some LPS or something.

When I ran high production, we used a lot of 1215 and 12L14. The 1215 gave a great surface finish, and the 12L14 you cold pretty much haul thru. At the time, 1018 always gave chip control issues, tho maybe with newer tooling this isn't the issue.