Alternative shafts for linear bearings

Whilst scrouging around a scrap yard I found a dozen or so new nippon
bearing company linear motion bearings(16mm ID & 13mm ID).Up until
now the idea was to go with rollerskate bearings on angle iron for
all 3 axis.
My Question: Are there alternatives to using expensive ground shafts
with these types of bearings?

I read somewhere (perhaps in this Group) that the hardened steel rod
used for making drill bits etc could be an alternative.

Thanks
Robert