Found it, thanks a bunch!
If I would venture a guess.... An M1905 Springfield, bayonet. I'm not sure about the "H" marking, I could do some more research on it. But I'm probably right about the model, or close to it. - C.J.
JM- Springfield marked an "H" on their bayonets, meaning "hardened". I found out that Springfield did this on their bayonets at that time, and Remington did not. I believe theirs was marked with an "R". I hope this helps you. - C.J.
I would call that bayonet a South Korean K-M1. According the the reference "Bayonets an Illustrated Hostory", by M. Brayley, a number of M1 bayonets that were utilized by the South Koreans were ground down so that their blades were the dimensions of US M4 bayonets. I have seen several of these and I think they were were then reparkerized, often crudely. I believe your bayonet is likely US WWII production ( because of the H mark, original m1905 bayonets wouldn't have this) that was likely surplus and reworked by the South Koreans.