AC current

I got a 12 volt relay from radio shack. here is the data sheet http://datasheet.octopart.com/R40-11D2-12-NTE-Electronics-datasheet-55584.pdf I am trying to figure out if this relay could generate AC (I understand the frequency would be limited to the relay's switch time. ) essentially I am trying to make a H-bridge.

I don't know if the data sheet says but this relay has 2, three pole switches (I think it is double pole double throw)

thank you for your help.

H-bridges are just four switches. And relays are switches so you can build a h-bridge out of relays.

Whether they will do a good job at that is a different question.

can a double pole double throw relay be used to make an h-bridge?

No, you need 2 single pole double throw relays to make an H-bridge that gives you forward, reverse and stop states.

can a double pole double throw relay be used to make an h-bridge?

Absolutely. Connect the load between the poles and the throws to power / ground.

can a double pole double throw relay be used to make an h-bridge?

See this link for a circuit:- http://www.thebox.myzen.co.uk/Workshop/Motors_1.html

Building your own H bridges is great to learn about them, but in an application if space is an issue - you're probably better off using an H bridge IC such as the LMD18200 or L298 as these have features such as overcurrent / overtemp protection, seperate enable functions, internal clamp diodes etc.