Circle Machine Co. (a product of Kennametal) S Series Straight Shank Steel Right-Handed Roughing Bar, No. SSBIC-625-7-5R. Shank diameter .625", overall length 7.00", minimum bore .680", bore depth 2.500", cutting tip height .010".
For more specifications see this Circle Machine Co. web page.
This tool is in very good working condition.