How ironic! I was thinking the same thing. Today, in another forum, a guy (he identified himself as such) was responding to another entry and mentioned that he was thinking about harming himself. He said he was holding the tool he used before but didn't do anything this time.
That made me think that I've never read or heard of a guy cutting himself (assuming SH to be cutting). I've read a lot of entries in the different forms here from females about SH/SI. Other web sites like this one must have their share of entries from females who self-harm, I would think.
So, I know of one male. Maybe males don't talk about it because they think it would be embarrassing.