As I don't have experience with the Ironman safe, I'm not sure how much this will help you, but if this helps you in your comparison, regarding the NF, it is a mid-level gun safe that has a 1/4 inch steel door, 11 gauge side armor, and a standard fire resistant design. Consequently, it is vulnerable to hand tool attacks and will provide only a limited amount of protection should any of the 5 other sides be attacked (it could give a minute or a few, but it also might give less.) For reference, the next model up, the BF, has several differences. It uses a 1/2 inch front plate, and 3/16 inches worth of side plates, making it more resistant to hand tool attacks. It also uses poured concrete for the fire insulating material, a design which is arguably a golden standard in slowing the speed in which the internal temperature in the safe rises. Both the NF and BF use the ETL fire rating, instead of the UL fire rating.
While the NF and BF both carry the RSC rating, how those safes would fare in attack can be very different. The RSC test has minimum construction requirements, but not maximum construction requirements. The test itself is a 5-minute, one-man test involving hand tools that must weigh less than either 3 or 3.5 pounds (can't remember which) and the attack focuses solely on the front door. So many RSCs fall most short when it comes to side armor. Where as a fire axe can pretty rapidly smash through a 12/11/10 gauge side wall, someone can bang away without success at the 1/4 inch side wall (like on the upgraded Ironman), or 3/16 on the BF and Sturdy safes IMO. Given the difference the upgrade to slightly thicker side armor can make, it might be a worthwhile contemplation for those wanting a safe that will survive a hand tool attack IMO, FWIW.
