Q: We need advice on a material that will deliver a tensile strength of 210 to 250 ksi, as well as help us protect against galling. The attaching areas are stainless steel Grade 8.
A: For this instance, we would suggest MP35N. This alloy was developed specifically for high strength and can provide an ultimate tensile strength of 250 ksi, even at 600°F.
In regards to the galling issue, MP35N is a nickel-cobalt alloy. Since MP35N is very different in composition to your base metal of stainless, and has a significantly different hardness it will have less change of galling. In general, the more different the alloys, the less chance to gall however we would recommend a lubricant to reduce the chance of galling even more.