Standard hole saws will cut thru the material, they are hardened blades, but go slow, die formers are here http://www.polyperformance.com/shop/Light-Racing-Flared-Hole-Dies-p-1619.html other places as well...

 

Thanks Rich

 

If you use a lot of cutting oil with your holesaw blades you can make them go a long way! DON'T buy cheap hole saws! I use Lenox or Milwaukie and have cut hundreds of holes with my set. The good ones I've even had resharpened for a few bucks a piece. Cheap ones will wear out on the first hole and nobody can ever sharpen them.