As for using a belt when lifting raw, no I do not think it will help.
Shirted benchers use a belt to hold the shirt in place. It is referred to as “jacking” the shirt. The collar in a bench shirt is stronger and thicker than the chest plate (usually), so the shirt is pulled down so that the collar can be utilized. If the shirt is not held in place with the belt, typically it will ride up into the neck, choking the lifter and now the lifter can’t get as much out of the shirt. Sometimes you will see a very thin belt being used for this. The lifter is using it solely to keep the shirt down.
But with that being said, if you can still keep a good arch and big belly with a belt on, and you feel it helps, then I don’t see any reason to not use it, so long as if you compete and it is allowed by your fed for raw benchers. I have used a belt when benching raw, just out of curiosity (I had seen equipped lifters using them, and didn’t know why) and didn’t feel that it helped at all. If anything, I thought that it hurt my arch. [/quote]
I disagree. I bench raw and I like to use a belt to push my stomach against as I take in a belly fully of air before lifting. It not only helps you keep your core tight but allows you to use it as a “cue” to start the lift.