In the event of a bear attack, is it procedure to punch him in the nose to save yourself?

It depends on the reason for the attack. If a bear is surprised or a mother bear is being defensive, crawling into a fetal position might help pacify the bear and convince it that you are no longer a threat. However, if the bear is attacking you in order to eat you, which is sometimes the case, this will not help. You will have to fight.

You're thinking of sharks. You could try that with a bear, but I suspect it would just make him mad (or madder). I think the best method of dealing with a bear attack is not to be there when it happens.

I remember reading somewhere that for a black bear- making a lot of noise and making yourself big is a useful tool. For a grizzly, however, you should just curl into a ball and cover your head in hopes it will leave you alone. Punching a black bear in the nose/face doesn't really seem like a useful tool, but may work. Grizzly however, I think you would just piss it off by doing that.

I just attended a Bear Safety course here in Idaho (we had two employees unknowingly walk into a bear's sleeping area. It was a grizzly - one was mauled a bit but the other had bear spray that worked perfectly so both survived). Best defense is a good offense in addition to wearing bells- bear spray. It is more effective than guns (because in the heat of the attack, people' aims are not great and you don't want to wound one). If you are still attacked, lie face down and cover the back of your head with your arms and hands. Play dead. You will be bit - it will hurt, but in the end it will probably leave you alone and you should survive. Do not run - they see that as a prey and they can outrun you every single time (it is a myth that they can't run downhill or uphill). Do not climb a tree, they can out climb you.

It's best to hit its face, eyes and nose.

no curl in a ball and cover your head then if he attacks punch him and run

Shoot first to save yourself. Punch him later.