Hey guys! Does anyone have any experience machining gold? I machine a lot of really hard materials like various hardened steels, titanium, Inconel, various grades of stainless, and even occasionally carbide (although that’s more grinding than machining). But I really don’t have much experience with machining precious metals. I’ve done some gold inlay work, but never machined it. A customer has a job for me that requires machining 20k gold (alloyed with silver). It will require both lathe and mill work. Does anyone have tooling and feed/speed suggestions? What is it’s machinability (does it machine like brass, or is it more gummy like aluminum)? Thanks in advance!

Edit: I took some test cuts and found a sweet spot. It really likes the ultra sharp and high polished tooling that I use on aluminum. It also seems to like 650 SFM. I might drop that down to 500 SFM for slotting. I am using solid carbide tooling, I’d imagine HSS would do well. I’d say is machines kinda like a copper alloy, but with almost no abrasion. It’s actually super nice to work on.