I need to resolve a damage/sunder attempt against a character's spiked-chain, but I can't figure out where on the chart of "damaging objects" a spiked-chain would fit, specifically whether it would be considered "hafted" or not. To me, it seems like a relatively fragile type of weapon that would have less hardness, but my personal brand of "common sense" frequently does not align well with the RAW.
So... Where on this chart would a spiked-chain fail in?
Two-handed blade? Two-handed hafted weapon?
I'd use the same stats as a two-handed blade; it's two-handed, and it is most certainly not hafted; it's all metal.
The term "hardness" is kind of misleading. Metals have strength (basically toughness) and hardness (basically sharpness). More of one essentially means less of the other. A super-hard steel (like stainless/surgical steel) can hold an incredible edge, but is very brittle. It can't bend and spring back, it'll shatter.
I feel like a chain would be one of the hardest weapons to sunder; no need for metallic harness, so it's just super strong, no specific weak points, and a bunch of interlocking pieces versus one large piece means energy won't transfer well and leverage will be very difficult to apply.
A Greatsword is a single piece of forged steel. It can’t bend or move to mitigate impact. The force of a Sunder attempt is going to reverberate from end to end and affect the entire piece.
A Spiked Chain is going wiggle when hit by a Sunder attempt. The individual link that is hit will move, reducing the impact. The links on either side will move, further increasing the impulse time. The next links will also move, and the next... each further reducing the impact by increasing the impulse time.
Physically, the chain is built to mitigate the effects of a Sunder attempt better than the Greatsword. But the game doesn't account for this dynamic, other than giving Whipwood a +2 against Sunder attempts for being flexible.