So, for you young guys, the "or I will quit" part of that threat is ALWAYS implied, no need to be said. Just makes you seem childish. Go ask for more money if you want to, but don't be an asshole until you have another offer lined up, and even then, don't be an asshole. When I was in tech I made double salary for months after I left jobs by asking for $150/hr to consult back to places after I left, and they'd always call and employ me 10-15 hours a week. The funny thing is, I was usually only actually "working" 10-15 hours a week anyway so I could get a lot of work done in that time, and they were happy about it. Haha.
No reason to ever threaten your boss, or let him know you will leave. If you are talented, they know damn well you have options and that you can leave. If they simply don't recognize your talent, then nothing you can do will educate them. You SHOULD leave. If you're not talented, then suck it up and be glad you're getting paid.