Hand Tools Archive
A couple of years ago when I made about two dozen planes, I was experimenting with chisels to find something that lasted well and didn't stick in the cut making the mortise. After initial excavation, sticking isn't an issue, but I recalled a discussion that earlier mortise chisels were relieved in their length.
I found a chisel type like this, Chinese and hss, and got a set. These seem like the same hss as muji irons, but this chisel sharpens well on Japanese natural stones, which is unusual. It's really fine in its edge taking and holds an edge for a really long time, but it didn't hold up at the ferrule because it's just stabbed into the handle.
I hate to say it, but it might be the best modern steel I've seen in a chisel, but the shape and construction method leaves a lot to be desired.