Cast steel molds?

Hey all,

So, came across a vid on IG someone posted about molds being made supposedly by casting steel over a ceramic male part.

I’ve been in the footwear industry almost 20 years and in china factories for (cumulatively) years, and have never seen this process. From what I know, steel molds are usually CNCd. I’ve seen molten aluminum cast for lasts, and assume the original block of steel may be cast before CNCing but the casting process never used for molds directly.

Doesn’t make any sense to me. Cast steel is not a normal or easy process (the workers in the vid were essentially pouring molten metal from a bucket into a mold by hand), is not that accurate (no castings are) and I can’t see any advantage. The guy who posted says it allows you to mold undercuts (I don’t see how you’d get the part out then), and molding texture (no way casting captures that fine details), and organic shapes (you can do organic in CNC).

He said it was a mold for compression molding rubber but is to be used for injection or any kind of mold. The positive ceramic part is first CNCd from wood, then cast in urethane, then cast in ceramic. Then used as the mold positive for the steel.

While I could be wrong, I’m open to learning. Anyone ever see cast steel for molds?

R

haven’t seen it either, but I’d like to learn more!

Me too, if it’s a thing.

I just think there’s some sort of misunderstanding of the process going on but love learning about new processes.

R

Doesn’t make any sense to me. Cast steel is not a normal or easy process (the workers in the vid were essentially pouring molten metal from a bucket into a mold by hand), is not that accurate (no castings are) and I can’t see any advantage. The guy who posted says it allows you to mold undercuts (I don’t see how you’d get the part out then), and molding texture (no way casting captures that fine details), and organic shapes (you can do organic in CNC).

I think it’s possible, Although I haven’t seen the process used for creating a compression or injection mold. Essentially the same as investment casting parts in ceramic shells. Very accurate with smooth surfaces, very fine detail. Stainless is commonly cast - golf club heads for example. Undercuts created by breaking out the ceramic.

can you post a link?

Yes, sounds like investment casting reversed, with a break-out ceramic part it allows large undercuts. But I would have to see the process to be able to evaluate.