What would this go to.

[lordbeezer]

Thinking I know it’s for measuring between centers. Came with a hardinge lathe years ago. Guy came by that has same model hardinge I had. Said it’s too small to fit on his bed. So any ideas?

 

[woodchucker]

It might be for a surface grinder or tool grinder for grinding on centers.
It also might be for a Browne and Sharpe measuring block. I have seen these beams and often thought that they need to have attachments to make that work for anything.

 

[benmychree]

Does not look like B&S to me, their tools are distinctive in their details.

 

[OTmachine]

Looks like parts of a Bench Centers, for checking runout. Missing the ways.

https://www.grainger.com/category/machining/precision-measuring-tools/inspection-calibration-tools-equipment/bench-centers