you can use stanley eye hooks for that
The I.D. of the eyelets is not particularly precise. Way off 5/8" to be sure. Crappy, ungraded metal, too.
If factory ones cannot be had, better to make them with a precisely sized section of tube, and a grade 5 or 8 bolt.
Doesn't need to be precise, just needs to pull the axle back to tension the chain.