Is it commonly done to investment cast Stainless Steel ?

There are two near me. I don't believe they accept hobbyist-sized jobs from overseas but you may find some help with suitable alloys and properties on their sites.

I haven't got details handy but a mate mentioned that there are a few companies that investment cast stainless steel down on the south coast Southampton and/or Portsmouth area mainly for marine fittings but he is involved in engine development. I've searched for it before and found a number of places that do it but have never enquired about minimum quantity or cost.

I recall all the work we did for a fishing tackle company were small parts made of Stainless 316 castings, made by the investment process. Cant remember the company that made them, just that it was either in Hitchin, Letchworth or Hatfield. A quick google brought up the company pasted below, but I don't know if this was the one in question. I also recall that the cored cross holes in the castings had awful hard spots, which made opening out the holes and tapping very difficult. Other holes were cast accurately to tapping hole size were ok for tapping.

Thanks for the replies,

Boo