Which Alloy Has Better Thermal Conductivity: 304 SS or SAE 516 Grade 70?

[cwgarr]

I am trying to decide what alloy I should use in an experimental heat transfer device. I am considering 2 materials- 304 Stainless Steel and SAE 516 Grade 70 boiler steel. I want to choose the material that has the best conductivity characteristics. To be clear, I want the material that has the best thermal transfer rate. Both metals would be approximately .125" thick and would be exposed to a source heat of 1000F.

 

[Astronuc]

http://www.alleghenytechnologies.com/ludlum/Documents/302_305.pdf

If one is exposing the metal to 1000 F then one should probably use 304H with additional carbon.

http://www.outokumpu.com/35045.epibrw