what oil is suitable to lubricate and protect moving parts from rust? Im thinking specifically the column of an old pillar drill, its very tightly machined to the platform so any rust will ruin it. WD40 just doesnt seem appropriate! Likewise 3-in-1 would be harder to apply. Is there something specific for the job?

I'd lather it in engine oil with a rag

i tend to do these things with a thin oil, like sewing machine oil. theres always been some in my garage its older than me) and i don't know what sae it is, but it does the trick

What's wrong with 3 in 1? I use it on my machine tools and just about everything apart from air tools which get air tool oil, a bit thicker than 3 in 1 and steam engines that get steam oil that is thick and sticky.

Caber

Ive used wd40 on machine tools for years, there is also a product called duck oil which is thicker and leaves a better coating on the surface.As said engine oil is also perfectly ok to use but more messy.
Paul.

Chain (or wire rope) lube