Machinability and hardening data for AISI 1566
I have a project for which I would like to use some excess Thomson linear shafting. I'm pretty sure it is 1566 which is basically 1070 with a bit of Mn (the shafting is etched with the Thomson logo and sparks out like 1070). It will involve annealing, machining and then harden/temper. But I can only find very limited reference to machinability and hardening information for 1566 on my web searches. The two references I found are very sketchy and somewhat contradictory on the hardening temperature. I don't have any good heat treatment texts and my copy of MH is of no help in this case.
Does anyone know sources for what to expect during machining (simple turning of 3/8" to 3/4" dia, drilling and tapping)? What is the recommended hardening temp and quenching medium?
These are non-critical parts that I will personally use in the shop for tool and work holding. I know that I could buy new steel but I strongly prefer to use existing stock that I otherwise have no use.
Last edited by Jim S.; 11-28-2011 at 08:21 PM.
Have a look here.
Or, for $25, you could buy a datasheet from Techstreet, which isn't cheap but might give more peace of mind.
Thanks for the links. I had actually found both these links in my searches but was hoping for more detail. The ASM tech sheet looks intriguing but I did not jump on it because the extract says 1566 has low hardenability. Which confuses me because the shafting that I have now is very hard at 65 HRC. I'll just experiment with the furnace.
"Hardenability" refers to how deeply or thoroughly a thick section hardens. A material with low hardenability can have a really hard surface with a tough (non-hard) core. A material with high hardenability is going to be more consistently hard through the entire section.
If low hardenability sounds a lot like case hardening, it should. However, typical case hardened alloys (e.g., 8620, 9310) require carburizing or nitriding to get a hard surface. Alloy 1566 should not, as it's got a healthy amount of carbon. However, its low hardenability means the hardness drops off below the surface.
Thank you for that explanation. Makes total sense now. 1566 should work for what I want to do.